Uplink Resource Management in Two-step Random-access Procedures

ABSTRACT

In some embodiments, a wireless device receives one or more messages including one or more configuration parameters of a cell. The one or more configuration parameters indicate physical uplink shared channel (PUSCH) resources for transmission of a message A (MsgA) payload of a two-step random-access procedure of the cell. The wireless device transmits, via a first PUSCH resource of the PUSCH resources, the MsgA payload for the two-step random-access procedure. Based on completing the two-step random-access procedure, the wireless device releases the PUSCH resources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 17/344,071, filed Jun. 10, 2021, which is acontinuation application of International Application No.PCT/US2020/012177, filed Jan. 3, 2020, which claims the benefit of U. S.Provisional Application No. 62/788,612, filed Jan. 4, 2019, the contentsof each of which are hereby incorporated by reference in theirentireties.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 2A is a diagram of an example user plane protocol stack as per anaspect of an embodiment of the present disclosure.

FIG. 2B is a diagram of an example control plane protocol stack as peran aspect of an embodiment of the present disclosure.

FIG. 3 is a diagram of an example wireless device and two base stationsas per an aspect of an embodiment of the present disclosure.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals as per an aspect of an embodiment of the presentdisclosure.

FIG. 5B is a diagram of an example downlink channel mapping and exampledownlink physical signals as per an aspect of an embodiment of thepresent disclosure.

FIG. 6 is a diagram depicting an example transmission time or receptiontime for a carrier as per an aspect of an embodiment of the presentdisclosure.

FIG. 7A and FIG. 7B are diagrams depicting example sets of OFDMsubcarriers as per an aspect of an embodiment of the present disclosure.

FIG. 8 is a diagram depicting example OFDM radio resources as per anaspect of an embodiment of the present disclosure.

FIG. 9A is a diagram depicting an example CSI-RS and/or SS blocktransmission in a multi-beam system.

FIG. 9B is a diagram depicting an example downlink beam managementprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 10 is an example diagram of configured bandwidth parts (BWPs) asper an aspect of an embodiment of the present disclosure.

FIG. 11A and FIG. 11B are diagrams of an example multi connectivity asper an aspect of an embodiment of the present disclosure.

FIG. 12 is a diagram of an example random access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 13 is a structure of example MAC entities as per an aspect of anembodiment of the present disclosure.

FIG. 14 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 15 is a diagram of example RRC states as per an aspect of anembodiment of the present disclosure.

FIG. 16 is an example of a two-step RA procedure as per an aspect of anembodiment of the present disclosure.

FIG. 17A, FIG. 17B, and FIG. 17C are examples of radio resourceallocations of a PRACH resource and one or more associated UL radioresources as per an aspect of an embodiment of the present disclosure.

FIG. 18A, FIG. 18B, and FIG. 18C are respectively examples of an RAR, aMAC subheader with backoff indicator, and a MAC subheader with RAPID asper an aspect of an embodiment of the present disclosure.

FIG. 19 is an example diagram of contention based and contention-freerandom access procedures with LBT as per an aspect of an embodiment ofthe present disclosure.

FIG. 20 is an example diagram of a two-step RA procedure with LBT as peran aspect of an embodiment of the present disclosure.

FIG. 21 is an example of radio resource allocation for a two-step RAprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 22 is an example of one or more LBTs performed for a two-step RAprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 23A and FIG. 23B are examples of one or more LBTs performed for atwo-step RA procedure in an unlicensed band as per an aspect of anembodiment of the present disclosure.

FIG. 24 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 25 is an example of association/mapping in a two-step random-accessprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 26 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 27 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 28 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 29 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 30 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 31 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 32 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 33 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 34 is an example of a random-access procedure as per an aspect ofan embodiment of the present disclosure.

FIG. 35 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 36 is an example flowchart of a random-access procedure as per anaspect of an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable operation ofrandom-access procedure. Embodiments of the technology disclosed hereinmay be employed in the technical field of multicarrier communicationsystems. More particularly, the embodiments of the technology disclosedherein may relate to random-access procedure in a multicarriercommunication system.

The following Acronyms are used throughout the present disclosure:

3GPP 3rd Generation Partnership Project

5GC 5G Core Network

ACK Acknowledgement

AMF Access and Mobility Management Function

ARQ Automatic Repeat Request

AS Access Stratum

ASIC Application-Specific Integrated Circuit

BA Bandwidth Adaptation

BCCH Broadcast Control Channel

BCH Broadcast Channel

BPSK Binary Phase Shift Keying

BWP Bandwidth Part

CA Carrier Aggregation

CC Component Carrier

CCCH Common Control CHannel

CDMA Code Division Multiple Access

CN Core Network

CP Cyclic Prefix

CP-OFDM Cyclic Prefix-Orthogonal Frequency Division Multiplex

C-RNTI Cell-Radio Network Temporary Identifier

CS Configured Scheduling

CSI Channel State Information

CSI-RS Channel State Information-Reference Signal

CQI Channel Quality Indicator

CSS Common Search Space

CU Central Unit

DC Dual Connectivity

DCCH Dedicated Control Channel

DCI Downlink Control Information

DL Downlink

DL-SCH Downlink Shared CHannel

DM-RS DeModulation Reference Signal

DRB Data Radio Bearer

DRX Discontinuous Reception

DTCH Dedicated Traffic Channel

DU Distributed Unit

EPC Evolved Packet Core

E-UTRA Evolved UMTS Terrestrial Radio Access

E-UTRAN Evolved-Universal Terrestrial Radio Access Network

FDD Frequency Division Duplex

FPGA Field Programmable Gate Arrays

F1-C F1-Control plane

F1-U F1-User plane

gNB next generation Node B

HARQ Hybrid Automatic Repeat reQuest

HDL Hardware Description Languages

IE Information Element

IP Internet Protocol

LCID Logical Channel Identifier

LTE Long Term Evolution

MAC Media Access Control

MCG Master Cell Group

MCS Modulation and Coding Scheme

MeNB Master evolved Node B

MIB Master Information Block

MME Mobility Management Entity

MN Master Node

NACK Negative Acknowledgement

NAS Non-Access Stratum

NG CP Next Generation Control Plane

NGC Next Generation Core

NG-C NG-Control plane

ng-eNB next generation evolved Node B

NG-U NG-User plane

NR New Radio

NR MAC New Radio MAC

NR PDCP New Radio PDCP

NR PHY New Radio PHYsical

NR RLC New Radio RLC

NR RRC New Radio RRC

NSSAI Network Slice Selection Assistance Information

O&M Operation and Maintenance

OFDM orthogonal Frequency Division Multiplexing

PBCH Physical Broadcast CHannel

PCC Primary Component Carrier

PCCH Paging Control CHannel

PCell Primary Cell

PCH Paging CHannel

PDCCH Physical Downlink Control CHannel

PDCP Packet Data Convergence Protocol

PDSCH Physical Downlink Shared CHannel

PDU Protocol Data Unit

PHICH Physical HARQ Indicator CHannel

PHY PHYsical

PLMN Public Land Mobile Network

PMI Precoding Matrix Indicator

PRACH Physical Random Access CHannel

PRB Physical Resource Block

PSCell Primary Secondary Cell

PSS Primary Synchronization Signal

pTAG primary Timing Advance Group

PT-RS Phase Tracking Reference Signal

PUCCH Physical Uplink Control CHannel

PUSCH Physical Uplink Shared CHannel

QAM Quadrature Amplitude Modulation

QFI Quality of Service Indicator

QoS Quality of Service

QPSK Quadrature Phase Shift Keying

RA Random Access

RACH Random Access CHannel

RAN Radio Access Network

RAT Radio Access Technology

RA-RNTI Random Access-Radio Network Temporary Identifier

RB Resource Blocks

RBG Resource Block Groups

RI Rank indicator

RLC Radio Link Control

RRC Radio Resource Control

RS Reference Signal

RSRP Reference Signal Received Power

SCC Secondary Component Carrier

SCell Secondary Cell

SCG Secondary Cell Group

SC-FDMA Single Carrier-Frequency Division Multiple Access

SDAP Service Data Adaptation Protocol

SDU Service Data Unit

SeNB Secondary evolved Node B

SFN System Frame Number

S-GW Serving GateWay

SI System Information

SIB System Information Block

SMF Session Management Function

SN Secondary Node

SpCell Special Cell

SRB Signaling Radio Bearer

SRS Sounding Reference Signal

SS Synchronization Signal

SSS Secondary Synchronization Signal

sTAG secondary Timing Advance Group

TA Timing Advance

TAG Timing Advance Group

TAI Tracking Area Identifier

TAT Time Alignment Timer

TB Transport Block

TC-RNTI Temporary Cell-Radio Network Temporary Identifier

TDD Time Division Duplex

TDMA Time Division Multiple Access

TTI Transmission Time Interval

UCI Uplink Control Information

UE User Equipment

UL Uplink

UL-SCH Uplink Shared CHannel

UPF User Plane Function

UPGW User Plane Gateway

VHDL VHSIC Hardware Description Language

Xn-C Xn-Control plane

Xn-U Xn-User plane

Example embodiments of the disclosure may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CodeDivision Multiple Access (CDMA), Orthogonal Frequency Division MultipleAccess (OFDMA), Time Division Multiple Access (TDMA), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement Quadrature Amplitude Modulation(QAM) using Binary Phase Shift Keying (BPSK), Quadrature Phase ShiftKeying (QPSK), 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and/or the like.Physical radio transmission may be enhanced by dynamically orsemi-dynamically changing the modulation and coding scheme depending ontransmission requirements and radio conditions.

FIG. 1 is an example Radio Access Network (RAN) architecture as per anaspect of an embodiment of the present disclosure. As illustrated inthis example, a RAN node may be a next generation Node B (gNB) (e.g.120A, 120B) providing New Radio (NR) user plane and control planeprotocol terminations towards a first wireless device (e.g. 110A). In anexample, a RAN node may be a next generation evolved Node B (ng-eNB)(e.g. 120C, 120D), providing Evolved UMTS Terrestrial Radio Access(E-UTRA) user plane and control plane protocol terminations towards asecond wireless device (e.g. 110B). The first wireless device maycommunicate with a gNB over a Uu interface. The second wireless devicemay communicate with a ng-eNB over a Uu interface.

A gNB or an ng-eNB may host functions such as radio resource managementand scheduling, IP header compression, encryption and integrityprotection of data, selection of Access and Mobility Management Function(AMF) at User Equipment (UE) attachment, routing of user plane andcontrol plane data, connection setup and release, scheduling andtransmission of paging messages (originated from the AMF), schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance (O&M)), measurement and measurementreporting configuration, transport level packet marking in the uplink,session management, support of network slicing, Quality of Service (QoS)flow management and mapping to data radio bearers, support of UEs inRRC_INACTIVE state, distribution function for Non-Access Stratum (NAS)messages, RAN sharing, dual connectivity or tight interworking betweenNR and E-UTRA.

In an example, one or more gNBs and/or one or more ng-eNBs may beinterconnected with each other by means of Xn interface. A gNB or anng-eNB may be connected by means of NG interfaces to 5G Core Network(5GC). In an example, 5GC may comprise one or more AMF/User PlanFunction (UPF) functions (e.g. 130A or 130B). A gNB or an ng-eNB may beconnected to a UPF by means of an NG-User plane (NG-U) interface. TheNG-U interface may provide delivery (e.g. non-guaranteed delivery) ofuser plane Protocol Data Units (PDUs) between a RAN node and the UPF. AgNB or an ng-eNB may be connected to an AMF by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide functions such asNG interface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, configurationtransfer or warning message transmission.

In an example, a UPF may host functions such as anchor point forintra-/inter-Radio Access Technology (RAT) mobility (when applicable),external PDU session point of interconnect to data network, packetrouting and forwarding, packet inspection and user plane part of policyrule enforcement, traffic usage reporting, uplink classifier to supportrouting traffic flows to a data network, branching point to supportmulti-homed PDU session, QoS handling for user plane, e.g. packetfiltering, gating, Uplink (UL)/Downlink (DL) rate enforcement, uplinktraffic verification (e.g. Service Data Flow (SDF) to QoS flow mapping),downlink packet buffering and/or downlink data notification triggering.

In an example, an AMF may host functions such as NAS signalingtermination, NAS signaling security, Access Stratum (AS) securitycontrol, inter Core Network (CN) node signaling for mobility between3^(rd) Generation Partnership Project (3GPP) access networks, idle modeUE reachability (e.g., control and execution of paging retransmission),registration area management, support of intra-system and inter-systemmobility, access authentication, access authorization including check ofroaming rights, mobility management control (subscription and policies),support of network slicing and/or Session Management Function (SMF)selection.

FIG. 2A is an example user plane protocol stack, where Service DataAdaptation Protocol (SDAP) (e.g. 211 and 221), Packet Data ConvergenceProtocol (PDCP) (e.g. 212 and 222), Radio Link Control (RLC) (e.g. 213and 223) and Media Access Control (MAC) (e.g. 214 and 224) sublayers andPhysical (PHY) (e.g. 215 and 225) layer may be terminated in wirelessdevice (e.g. 110) and gNB (e.g. 120) on the network side. In an example,a PHY layer provides transport services to higher layers (e.g. MAC, RRC,etc). In an example, services and functions of a MAC sublayer maycomprise mapping between logical channels and transport channels,multiplexing/demultiplexing of MAC Service Data Units (SDUs) belongingto one or different logical channels into/from Transport Blocks (TBs)delivered to/from the PHY layer, scheduling information reporting, errorcorrection through Hybrid Automatic Repeat request (HARQ) (e.g. one HARQentity per carrier in case of Carrier Aggregation (CA)), priorityhandling between UEs by means of dynamic scheduling, priority handlingbetween logical channels of one UE by means of logical channelprioritization, and/or padding. A MAC entity may support one or multiplenumerologies and/or transmission timings. In an example, mappingrestrictions in a logical channel prioritization may control whichnumerology and/or transmission timing a logical channel may use. In anexample, an RLC sublayer may supports transparent mode (TM),unacknowledged mode (UM) and acknowledged mode (AM) transmission modes.The RLC configuration may be per logical channel with no dependency onnumerologies and/or Transmission Time Interval (TTI) durations. In anexample, Automatic Repeat Request (ARQ) may operate on any of thenumerologies and/or TTI durations the logical channel is configuredwith. In an example, services and functions of the PDCP layer for theuser plane may comprise sequence numbering, header compression anddecompression, transfer of user data, reordering and duplicatedetection, PDCP PDU routing (e.g. in case of split bearers),retransmission of PDCP SDUs, ciphering, deciphering and integrityprotection, PDCP SDU discard, PDCP re-establishment and data recoveryfor RLC AM, and/or duplication of PDCP PDUs. In an example, services andfunctions of SDAP may comprise mapping between a QoS flow and a dataradio bearer. In an example, services and functions of SDAP may comprisemapping Quality of Service Indicator (QFI) in DL and UL packets. In anexample, a protocol entity of SDAP may be configured for an individualPDU session.

FIG. 2B is an example control plane protocol stack where PDCP (e.g. 233and 242), RLC (e.g. 234 and 243) and MAC (e.g. 235 and 244) sublayersand PHY (e.g. 236 and 245) layer may be terminated in wireless device(e.g. 110) and gNB (e.g. 120) on a network side and perform service andfunctions described above. In an example, RRC (e.g. 232 and 241) may beterminated in a wireless device and a gNB on a network side. In anexample, services and functions of RRC may comprise broadcast of systeminformation related to AS and NAS, paging initiated by 5GC or RAN,establishment, maintenance and release of an RRC connection between theUE and RAN, security functions including key management, establishment,configuration, maintenance and release of Signaling Radio Bearers (SRBs)and Data Radio Bearers (DRBs), mobility functions, QoS managementfunctions, UE measurement reporting and control of the reporting,detection of and recovery from radio link failure, and/or NAS messagetransfer to/from NAS from/to a UE. In an example, NAS control protocol(e.g. 231 and 251) may be terminated in the wireless device and AMF(e.g. 130) on a network side and may perform functions such asauthentication, mobility management between a UE and a AMF for 3GPPaccess and non-3GPP access, and session management between a UE and aSMF for 3GPP access and non-3GPP access.

In an example, a base station may configure a plurality of logicalchannels for a wireless device. A logical channel in the plurality oflogical channels may correspond to a radio bearer and the radio bearermay be associated with a QoS requirement. In an example, a base stationmay configure a logical channel to be mapped to one or moreTTIs/numerologies in a plurality of TTIs/numerologies. The wirelessdevice may receive a Downlink Control Information (DCI) via PhysicalDownlink Control CHannel (PDCCH) indicating an uplink grant. In anexample, the uplink grant may be for a first TTI/numerology and mayindicate uplink resources for transmission of a transport block. Thebase station may configure each logical channel in the plurality oflogical channels with one or more parameters to be used by a logicalchannel prioritization procedure at the MAC layer of the wirelessdevice. The one or more parameters may comprise priority, prioritizedbit rate, etc. A logical channel in the plurality of logical channelsmay correspond to one or more buffers comprising data associated withthe logical channel. The logical channel prioritization procedure mayallocate the uplink resources to one or more first logical channels inthe plurality of logical channels and/or one or more MAC ControlElements (CEs). The one or more first logical channels may be mapped tothe first TTI/numerology. The MAC layer at the wireless device maymultiplex one or more MAC CEs and/or one or more MAC SDUs (e.g., logicalchannel) in a MAC PDU (e.g., transport block). In an example, the MACPDU may comprise a MAC header comprising a plurality of MAC sub-headers.A MAC sub-header in the plurality of MAC sub-headers may correspond to aMAC CE or a MAC SUD (logical channel) in the one or more MAC CEs and/orone or more MAC SDUs. In an example, a MAC CE or a logical channel maybe configured with a Logical Channel IDentifier (LCID). In an example,LCID for a logical channel or a MAC CE may be fixed/pre-configured. Inan example, LCID for a logical channel or MAC CE may be configured forthe wireless device by the base station. The MAC sub-headercorresponding to a MAC CE or a MAC SDU may comprise LCID associated withthe MAC CE or the MAC SDU.

In an example, a base station may activate and/or deactivate and/orimpact one or more processes (e.g., set values of one or more parametersof the one or more processes or start and/or stop one or more timers ofthe one or more processes) at the wireless device by employing one ormore MAC commands. The one or more MAC commands may comprise one or moreMAC control elements. In an example, the one or more processes maycomprise activation and/or deactivation of PDCP packet duplication forone or more radio bearers. The base station may transmit a MAC CEcomprising one or more fields, the values of the fields indicatingactivation and/or deactivation of PDCP duplication for the one or moreradio bearers. In an example, the one or more processes may compriseChannel State Information (CSI) transmission of on one or more cells.The base station may transmit one or more MAC CEs indicating activationand/or deactivation of the CSI transmission on the one or more cells. Inan example, the one or more processes may comprise activation ordeactivation of one or more secondary cells. In an example, the basestation may transmit a MA CE indicating activation or deactivation ofone or more secondary cells. In an example, the base station maytransmit one or more MAC CEs indicating starting and/or stopping one ormore Discontinuous Reception (DRX) timers at the wireless device. In anexample, the base station may transmit one or more MAC CEs indicatingone or more timing advance values for one or more Timing Advance Groups(TAGs).

FIG. 3 is a block diagram of base stations (base station 1, 120A, andbase station 2, 120B) and a wireless device 110. A wireless device maybe called an UE. A base station may be called a NB, eNB, gNB, and/orng-eNB. In an example, a wireless device and/or a base station may actas a relay node. The base station 1, 120A, may comprise at least onecommunication interface 320A (e.g. a wireless modem, an antenna, a wiredmodem, and/or the like), at least one processor 321A, and at least oneset of program code instructions 323A stored in non-transitory memory322A and executable by the at least one processor 321A. The base station2, 120B, may comprise at least one communication interface 320B, atleast one processor 321B, and at least one set of program codeinstructions 323B stored in non-transitory memory 322B and executable bythe at least one processor 321B.

A base station may comprise many sectors for example: 1, 2, 3, 4, or 6sectors. A base station may comprise many cells, for example, rangingfrom 1 to 50 cells or more. A cell may be categorized, for example, as aprimary cell or secondary cell. At Radio Resource Control (RRC)connection establishment/re-establishment/handover, one serving cell mayprovide the NAS (non-access stratum) mobility information (e.g. TrackingArea Identifier (TAI)). At RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, a carrier correspondingto the PCell may be a DL Primary Component Carrier (PCC), while in theuplink, a carrier may be an UL PCC. Depending on wireless devicecapabilities, Secondary Cells (SCells) may be configured to formtogether with a PCell a set of serving cells. In a downlink, a carriercorresponding to an SCell may be a downlink secondary component carrier(DL SCC), while in an uplink, a carrier may be an uplink secondarycomponent carrier (UL SCC). An SCell may or may not have an uplinkcarrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and a cell index. A carrier (downlinkor uplink) may belong to one cell. The cell ID or cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the disclosure, a cell ID may be equallyreferred to a carrier ID, and a cell index may be referred to a carrierindex. In an implementation, a physical cell ID or a cell index may beassigned to a cell. A cell ID may be determined using a synchronizationsignal transmitted on a downlink carrier. A cell index may be determinedusing RRC messages. For example, when the disclosure refers to a firstphysical cell ID for a first downlink carrier, the disclosure may meanthe first physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the disclosure indicates that a first carrier is activated, thespecification may equally mean that a cell comprising the first carrieris activated.

A base station may transmit to a wireless device one or more messages(e.g. RRC messages) comprising a plurality of configuration parametersfor one or more cells. One or more cells may comprise at least oneprimary cell and at least one secondary cell. In an example, an RRCmessage may be broadcasted or unicasted to the wireless device. In anexample, configuration parameters may comprise common parameters anddedicated parameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and NAS; paginginitiated by 5GC and/or NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and NG-RAN, whichmay comprise at least one of addition, modification and release ofcarrier aggregation; or addition, modification, and/or release of dualconnectivity in NR or between E-UTRA and NR. Services and/or functionsof an RRC sublayer may further comprise at least one of securityfunctions comprising key management; establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and/orData Radio Bearers (DRBs); mobility functions which may comprise atleast one of a handover (e.g. intra NR mobility or inter-RAT mobility)and a context transfer; or a wireless device cell selection andreselection and control of cell selection and reselection. Servicesand/or functions of an RRC sublayer may further comprise at least one ofQoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; or NAS message transfer to/from a core network entity (e.g.AMF, Mobility Management Entity (MME)) from/to the wireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive stateand/or an RRC Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection/re-selection; monitoring/receiving a paging for mobileterminated data initiated by 5GC; paging for mobile terminated data areamanaged by 5GC; or DRX for CN paging configured via NAS. In anRRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection/re-selection;monitoring/receiving a RAN/CN paging initiated by NG-RAN/5GC; RAN-basednotification area (RNA) managed by NG-RAN; or DRX for RAN/CN pagingconfigured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, abase station (e.g. NG-RAN) may keep a 5GC-NG-RAN connection (bothC/U-planes) for the wireless device; and/or store a UE AS context forthe wireless device. In an RRC_Connected state of a wireless device, abase station (e.g. NG-RAN) may perform at least one of: establishment of5GC-NG-RAN connection (both C/U-planes) for the wireless device; storinga UE AS context for the wireless device; transmit/receive of unicastdata to/from the wireless device; or network-controlled mobility basedon measurement results received from the wireless device. In anRRC_Connected state of a wireless device, an NG-RAN may know a cell thatthe wireless device belongs to.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and information foracquiring any other SI broadcast periodically or provisioned on-demand,i.e. scheduling information. The other SI may either be broadcast, or beprovisioned in a dedicated manner, either triggered by a network or uponrequest from a wireless device. A minimum SI may be transmitted via twodifferent downlink channels using different messages (e.g.MasterInformationBlock and SystemInformationBlockType1). An other SI maybe transmitted via SystemInformationBlockType2. For a wireless device inan RRC_Connected state, dedicated RRC signalling may be employed for therequest and delivery of the other SI. For the wireless device in theRRC_Idle state and/or the RRC_Inactive state, the request may trigger arandom-access procedure.

A wireless device may report its radio access capability informationwhich may be static. A base station may request what capabilities for awireless device to report based on band information. When allowed by anetwork, a temporary capability restriction request may be sent by thewireless device to signal the limited availability of some capabilities(e.g. due to hardware sharing, interference or overheating) to the basestation. The base station may confirm or reject the request. Thetemporary capability restriction may be transparent to 5GC (e.g., staticcapabilities may be stored in 5GC).

When CA is configured, a wireless device may have an RRC connection witha network. At RRC connection establishment/re-establishment/handoverprocedure, one serving cell may provide NAS mobility information, and atRRC connection re-establishment/handover, one serving cell may provide asecurity input. This cell may be referred to as the PCell. Depending onthe capabilities of the wireless device, SCells may be configured toform together with the PCell a set of serving cells. The configured setof serving cells for the wireless device may comprise one PCell and oneor more SCells.

The reconfiguration, addition and removal of SCells may be performed byRRC. At intra-NR handover, RRC may also add, remove, or reconfigureSCells for usage with the target PCell. When adding a new SCell,dedicated RRC signalling may be employed to send all required systeminformation of the SCell i.e. while in connected mode, wireless devicesmay not need to acquire broadcasted system information directly from theSCells.

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g. to establish, modify and/or release RBs,to perform handover, to setup, modify, and/or release measurements, toadd, modify, and/or release SCells and cell groups). As part of the RRCconnection reconfiguration procedure, NAS dedicated information may betransferred from the network to the wireless device. TheRRCConnectionReconfiguration message may be a command to modify an RRCconnection. It may convey information for measurement configuration,mobility control, radio resource configuration (e.g. RBs, MAC mainconfiguration and physical channel configuration) comprising anyassociated dedicated NAS information and security configuration. If thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList, the wireless device may perform an SCell release. Ifthe received RRC Connection Reconfiguration message includes thesCellToAddModList, the wireless device may perform SCell additions ormodification.

An RRC connection establishment (or reestablishment, resume) proceduremay be to establish (or reestablish, resume) an RRC connection. an RRCconnection establishment procedure may comprise SRB1 establishment. TheRRC connection establishment procedure may be used to transfer theinitial NAS dedicated information/message from a wireless device toE-UTRAN. The RRCConnectionReestablishment message may be used tore-establish SRB1.

A measurement report procedure may be to transfer measurement resultsfrom a wireless device to NG-RAN. The wireless device may initiate ameasurement report procedure after successful security activation. Ameasurement report message may be employed to transmit measurementresults.

The wireless device 110 may comprise at least one communicationinterface 310 (e.g. a wireless modem, an antenna, and/or the like), atleast one processor 314, and at least one set of program codeinstructions 316 stored in non-transitory memory 315 and executable bythe at least one processor 314. The wireless device 110 may furthercomprise at least one of at least one speaker/microphone 311, at leastone keypad 312, at least one display/touchpad 313, at least one powersource 317, at least one global positioning system (GPS) chipset 318,and other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of thebase station 1 120A, and/or the processor 321B of the base station 2120B may comprise at least one of a general-purpose processor, a digitalsignal processor (DSP), a controller, a microcontroller, an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) and/or other programmable logic device, discrete gate and/ortransistor logic, discrete hardware components, and the like. Theprocessor 314 of the wireless device 110, the processor 321A in basestation 1 120A, and/or the processor 321B in base station 2 120B mayperform at least one of signal coding/processing, data processing, powercontrol, input/output processing, and/or any other functionality thatmay enable the wireless device 110, the base station 1 120A and/or thebase station 2 120B to operate in a wireless environment.

The processor 314 of the wireless device 110 may be connected to thespeaker/microphone 311, the keypad 312, and/or the display/touchpad 313.The processor 314 may receive user input data from and/or provide useroutput data to the speaker/microphone 311, the keypad 312, and/or thedisplay/touchpad 313. The processor 314 in the wireless device 110 mayreceive power from the power source 317 and/or may be configured todistribute the power to the other components in the wireless device 110.The power source 317 may comprise at least one of one or more dry cellbatteries, solar cells, fuel cells, and the like. The processor 314 maybe connected to the GPS chipset 318. The GPS chipset 318 may beconfigured to provide geographic location information of the wirelessdevice 110.

The processor 314 of the wireless device 110 may further be connected toother peripherals 319, which may comprise one or more software and/orhardware modules that provide additional features and/orfunctionalities. For example, the peripherals 319 may comprise at leastone of an accelerometer, a satellite transceiver, a digital camera, auniversal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, and thelike.

The communication interface 320A of the base station 1, 120A, and/or thecommunication interface 320B of the base station 2, 120B, may beconfigured to communicate with the communication interface 310 of thewireless device 110 via a wireless link 330A and/or a wireless link 330Brespectively. In an example, the communication interface 320A of thebase station 1, 120A, may communicate with the communication interface320B of the base station 2 and other RAN and core network nodes.

The wireless link 330A and/or the wireless link 330B may comprise atleast one of a bi-directional link and/or a directional link. Thecommunication interface 310 of the wireless device 110 may be configuredto communicate with the communication interface 320A of the base station1 120A and/or with the communication interface 320B of the base station2 120B. The base station 1 120A and the wireless device 110 and/or thebase station 2 120B and the wireless device 110 may be configured tosend and receive transport blocks via the wireless link 330A and/or viathe wireless link 330B, respectively. The wireless link 330A and/or thewireless link 330B may employ at least one frequency carrier. Accordingto some of various aspects of embodiments, transceiver(s) may beemployed. A transceiver may be a device that comprises both atransmitter and a receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in thecommunication interface 310, 320A, 320B and the wireless link 330A, 330Bare illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6, FIG. 7A,FIG. 7B, FIG. 8, and associated text.

In an example, other nodes in a wireless network (e.g. AMF, UPF, SMF,etc) may comprise one or more communication interfaces, one or moreprocessors, and memory storing instructions.

A node (e.g. wireless device, base station, AMF, SMF, UPF, servers,switches, antennas, and/or the like) may comprise one or moreprocessors, and memory storing instructions that when executed by theone or more processors causes the node to perform certain processesand/or functions. Example embodiments may enable operation ofsingle-carrier and/or multi-carrier communications. Other exampleembodiments may comprise a non-transitory tangible computer readablemedia comprising instructions executable by one or more processors tocause operation of single-carrier and/or multi-carrier communications.Yet other example embodiments may comprise an article of manufacturethat comprises a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a node to enable operation ofsingle-carrier and/or multi-carrier communications. The node may includeprocessors, memory, interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, afirmware interface, a software interface, and/or a combination thereof.The hardware interface may comprise connectors, wires, electronicdevices such as drivers, amplifiers, and/or the like. The softwareinterface may comprise code stored in a memory device to implementprotocol(s), protocol layers, communication drivers, device drivers,combinations thereof, and/or the like. The firmware interface maycomprise a combination of embedded hardware and code stored in and/or incommunication with a memory device to implement connections, electronicdevice operations, protocol(s), protocol layers, communication drivers,device drivers, hardware operations, combinations thereof, and/or thelike.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure. FIG. 4A shows an example uplink transmitter forat least one physical channel. A baseband signal representing a physicaluplink shared channel may perform one or more functions. The one or morefunctions may comprise at least one of: scrambling; modulation ofscrambled bits to generate complex-valued symbols; mapping of thecomplex-valued modulation symbols onto one or several transmissionlayers; transform precoding to generate complex-valued symbols;precoding of the complex-valued symbols; mapping of precodedcomplex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 4A. These functions are illustrated as examples andit is anticipated that other mechanisms may be implemented in variousembodiments.

An example structure for modulation and up-conversion to the carrierfrequency of the complex-valued SC-FDMA or CP-OFDM baseband signal foran antenna port and/or the complex-valued Physical Random Access CHannel(PRACH) baseband signal is shown in FIG. 4B. Filtering may be employedprior to transmission.

An example structure for downlink transmissions is shown in FIG. 4C. Thebaseband signal representing a downlink physical channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

In an example, a gNB may transmit a first symbol and a second symbol onan antenna port, to a wireless device. The wireless device may infer thechannel (e.g., fading gain, multipath delay, etc.) for conveying thesecond symbol on the antenna port, from the channel for conveying thefirst symbol on the antenna port. In an example, a first antenna portand a second antenna port may be quasi co-located if one or morelarge-scale properties of the channel over which a first symbol on thefirst antenna port is conveyed may be inferred from the channel overwhich a second symbol on a second antenna port is conveyed. The one ormore large-scale properties may comprise at least one of: delay spread;doppler spread; doppler shift; average gain; average delay; and/orspatial Receiving (Rx) parameters.

An example modulation and up-conversion to the carrier frequency of thecomplex-valued OFDM baseband signal for an antenna port is shown in FIG.4D. Filtering may be employed prior to transmission.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals. FIG. 5B is a diagram of an example downlinkchannel mapping and a downlink physical signals. In an example, aphysical layer may provide one or more information transfer services toa MAC and/or one or more higher layers. For example, the physical layermay provide the one or more information transfer services to the MAC viaone or more transport channels. An information transfer service mayindicate how and with what characteristics data are transferred over theradio interface.

In an example embodiment, a radio network may comprise one or moredownlink and/or uplink transport channels. For example, a diagram inFIG. 5A shows example uplink transport channels comprising Uplink-SharedCHannel (UL-SCH) 501 and Random Access CHannel (RACH) 502. A diagram inFIG. 5B shows example downlink transport channels comprisingDownlink-Shared CHannel (DL-SCH) 511, Paging CHannel (PCH) 512, andBroadcast CHannel (BCH) 513. A transport channel may be mapped to one ormore corresponding physical channels. For example, UL-SCH 501 may bemapped to Physical Uplink Shared CHannel (PUSCH) 503. RACH 502 may bemapped to PRACH 505. DL-SCH 511 and PCH 512 may be mapped to PhysicalDownlink Shared CHannel (PDSCH) 514. BCH 513 may be mapped to PhysicalBroadcast CHannel (PBCH) 516.

There may be one or more physical channels without a correspondingtransport channel. The one or more physical channels may be employed forUplink Control Information (UCI) 509 and/or Downlink Control Information(DCI) 517. For example, Physical Uplink Control CHannel (PUCCH) 504 maycarry UCI 509 from a UE to a base station. For example, PhysicalDownlink Control CHannel (PDCCH) 515 may carry DCI 517 from a basestation to a UE. NR may support UCI 509 multiplexing in PUSCH 503 whenUCI 509 and PUSCH 503 transmissions may coincide in a slot at least inpart. The UCI 509 may comprise at least one of CSI, Acknowledgement(ACK)/Negative Acknowledgement (NACK), and/or scheduling request. TheDCI 517 on PDCCH 515 may indicate at least one of following: one or moredownlink assignments and/or one or more uplink scheduling grants

In uplink, a UE may transmit one or more Reference Signals (RSs) to abase station. For example, the one or more RSs may be at least one ofDemodulation-RS (DM-RS) 506, Phase Tracking-RS (PT-RS) 507, and/orSounding RS (SRS) 508. In downlink, a base station may transmit (e.g.,unicast, multicast, and/or broadcast) one or more RSs to a UE. Forexample, the one or more RSs may be at least one of PrimarySynchronization Signal (PSS)/Secondary Synchronization Signal (SSS) 521,CSI-RS 522, DM-RS 523, and/or PT-RS 524.

In an example, a UE may transmit one or more uplink DM-RSs 506 to a basestation for channel estimation, for example, for coherent demodulationof one or more uplink physical channels (e.g., PUSCH 503 and/or PUCCH504). For example, a UE may transmit a base station at least one uplinkDM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at least oneuplink DM-RS 506 may be spanning a same frequency range as acorresponding physical channel. In an example, a base station mayconfigure a UE with one or more uplink DM-RS configurations. At leastone DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may beconfigured to transmit at one or more symbols of a PUSCH and/or PUCCH. Abase station may semi-statistically configure a UE with a maximum numberof front-loaded DM-RS symbols for PUSCH and/or PUCCH. For example, a UEmay schedule a single-symbol DM-RS and/or double symbol DM-RS based on amaximum number of front-loaded DM-RS symbols, wherein a base station mayconfigure the UE with one or more additional uplink DM-RS for PUSCHand/or PUCCH. A new radio network may support, e.g., at least forCP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RSlocation, DM-RS pattern, and/or scrambling sequence may be same ordifferent.

In an example, whether uplink PT-RS 507 is present or not may depend ona RRC configuration. For example, a presence of uplink PT-RS may beUE-specifically configured. For example, a presence and/or a pattern ofuplink PT-RS 507 in a scheduled resource may be UE-specificallyconfigured by a combination of RRC signaling and/or association with oneor more parameters employed for other purposes (e.g., Modulation andCoding Scheme (MCS)) which may be indicated by DCI. When configured, adynamic presence of uplink PT-RS 507 may be associated with one or moreDCI parameters comprising at least MCS. A radio network may supportplurality of uplink PT-RS densities defined in time/frequency domain.When present, a frequency domain density may be associated with at leastone configuration of a scheduled bandwidth. A UE may assume a sameprecoding for a DMRS port and a PT-RS port. A number of PT-RS ports maybe fewer than a number of DM-RS ports in a scheduled resource. Forexample, uplink PT-RS 507 may be confined in the scheduledtime/frequency duration for a UE.

In an example, a UE may transmit SRS 508 to a base station for channelstate estimation to support uplink channel dependent scheduling and/orlink adaptation. For example, SRS 508 transmitted by a UE may allow fora base station to estimate an uplink channel state at one or moredifferent frequencies. A base station scheduler may employ an uplinkchannel state to assign one or more resource blocks of good quality foran uplink PUSCH transmission from a UE. A base station maysemi-statistically configure a UE with one or more SRS resource sets.For an SRS resource set, a base station may configure a UE with one ormore SRS resources. An SRS resource set applicability may be configuredby a higher layer (e.g., RRC) parameter. For example, when a higherlayer parameter indicates beam management, a SRS resource in each of oneor more SRS resource sets may be transmitted at a time instant. A UE maytransmit one or more SRS resources in different SRS resource setssimultaneously. A new radio network may support aperiodic, periodicand/or semi-persistent SRS transmissions. A UE may transmit SRSresources based on one or more trigger types, wherein the one or moretrigger types may comprise higher layer signaling (e.g., RRC) and/or oneor more DCI formats (e.g., at least one DCI format may be employed for aUE to select at least one of one or more configured SRS resource sets.An SRS trigger type 0 may refer to an SRS triggered based on a higherlayer signaling. An SRS trigger type 1 may refer to an SRS triggeredbased on one or more DCI formats. In an example, when PUSCH 503 and SRS508 are transmitted in a same slot, a UE may be configured to transmitSRS 508 after a transmission of PUSCH 503 and corresponding uplink DM-RS506.

In an example, a base station may semi-statistically configure a UE withone or more SRS configuration parameters indicating at least one offollowing: a SRS resource configuration identifier, a number of SRSports, time domain behavior of SRS resource configuration (e.g., anindication of periodic, semi-persistent, or aperiodic SRS), slot(mini-slot, and/or subframe) level periodicity and/or offset for aperiodic and/or aperiodic SRS resource, a number of OFDM symbols in aSRS resource, starting OFDM symbol of a SRS resource, a SRS bandwidth, afrequency hopping bandwidth, a cyclic shift, and/or a SRS sequence ID.

In an example, in a time domain, an SS/PBCH block may comprise one ormore OFDM symbols (e.g., 4 OFDM symbols numbered in increasing orderfrom 0 to 3) within the SS/PBCH block. An SS/PBCH block may comprisePSS/SSS 521 and PBCH 516. In an example, in the frequency domain, anSS/PBCH block may comprise one or more contiguous subcarriers (e.g., 240contiguous subcarriers with the subcarriers numbered in increasing orderfrom 0 to 239) within the SS/PBCH block. For example, a PSS/SSS 521 mayoccupy 1 OFDM symbol and 127 subcarriers. For example, PBCH 516 may spanacross 3 OFDM symbols and 240 subcarriers. A UE may assume that one ormore SS/PBCH blocks transmitted with a same block index may be quasico-located, e.g., with respect to Doppler spread, Doppler shift, averagegain, average delay, and spatial Rx parameters. A UE may not assumequasi co-location for other SS/PBCH block transmissions. A periodicityof an SS/PBCH block may be configured by a radio network (e.g., by anRRC signaling) and one or more time locations where the SS/PBCH blockmay be sent may be determined by sub-carrier spacing. In an example, aUE may assume a band-specific sub-carrier spacing for an SS/PBCH blockunless a radio network has configured a UE to assume a differentsub-carrier spacing.

In an example, downlink CSI-RS 522 may be employed for a UE to acquirechannel state information. A radio network may support periodic,aperiodic, and/or semi-persistent transmission of downlink CSI-RS 522.For example, a base station may semi-statistically configure and/orreconfigure a UE with periodic transmission of downlink CSI-RS 522. Aconfigured CSI-RS resources may be activated ad/or deactivated. Forsemi-persistent transmission, an activation and/or deactivation ofCSI-RS resource may be triggered dynamically. In an example, CSI-RSconfiguration may comprise one or more parameters indicating at least anumber of antenna ports. For example, a base station may configure a UEwith 32 ports. A base station may semi-statistically configure a UE withone or more CSI-RS resource sets. One or more CSI-RS resources may beallocated from one or more CSI-RS resource sets to one or more UEs. Forexample, a base station may semi-statistically configure one or moreparameters indicating CSI RS resource mapping, for example, time-domainlocation of one or more CSI-RS resources, a bandwidth of a CSI-RSresource, and/or a periodicity. In an example, a UE may be configured toemploy a same OFDM symbols for downlink CSI-RS 522 and control resourceset (coreset) when the downlink CSI-RS 522 and coreset are spatiallyquasi co-located and resource elements associated with the downlinkCSI-RS 522 are the outside of PRBs configured for coreset. In anexample, a UE may be configured to employ a same OFDM symbols fordownlink CSI-RS 522 and SS/PBCH blocks when the downlink CSI-RS 522 andSS/PBCH blocks are spatially quasi co-located and resource elementsassociated with the downlink CSI-RS 522 are the outside of PRBsconfigured for SS/PBCH blocks.

In an example, a UE may transmit one or more downlink DM-RSs 523 to abase station for channel estimation, for example, for coherentdemodulation of one or more downlink physical channels (e.g., PDSCH514). For example, a radio network may support one or more variableand/or configurable DM-RS patterns for data demodulation. At least onedownlink DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). A base station may semi-statisticallyconfigure a UE with a maximum number of front-loaded DM-RS symbols forPDSCH 514. For example, a DM-RS configuration may support one or moreDM-RS ports. For example, for single user-MIMO, a DM-RS configurationmay support at least 8 orthogonal downlink DM-RS ports. For example, formultiuser-MIMO, a DM-RS configuration may support 12 orthogonal downlinkDM-RS ports. A radio network may support, e.g., at least for CP-OFDM, acommon DM-RS structure for DL and UL, wherein a DM-RS location, DM-RSpattern, and/or scrambling sequence may be same or different.

In an example, whether downlink PT-RS 524 is present or not may dependon a RRC configuration. For example, a presence of downlink PT-RS 524may be UE-specifically configured. For example, a presence and/or apattern of downlink PT-RS 524 in a scheduled resource may beUE-specifically configured by a combination of RRC signaling and/orassociation with one or more parameters employed for other purposes(e.g., MCS) which may be indicated by DCI. When configured, a dynamicpresence of downlink PT-RS 524 may be associated with one or more DCIparameters comprising at least MCS. A radio network may supportplurality of PT-RS densities defined in time/frequency domain. Whenpresent, a frequency domain density may be associated with at least oneconfiguration of a scheduled bandwidth. A UE may assume a same precodingfor a DMRS port and a PT-RS port. A number of PT-RS ports may be fewerthan a number of DM-RS ports in a scheduled resource. For example,downlink PT-RS 524 may be confined in the scheduled time/frequencyduration for a UE.

FIG. 6 is a diagram depicting an example transmission time and receptiontime for a carrier as per an aspect of an embodiment of the presentdisclosure. A multicarrier OFDM communication system may include one ormore carriers, for example, ranging from 1 to 32 carriers, in case ofcarrier aggregation, or ranging from 1 to 64 carriers, in case of dualconnectivity. Different radio frame structures may be supported (e.g.,for FDD and for TDD duplex mechanisms). FIG. 6 shows an example frametiming. Downlink and uplink transmissions may be organized into radioframes 601. In this example, radio frame duration is 10 ms. In thisexample, a 10 ms radio frame 601 may be divided into ten equally sizedsubframes 602 with 1 ms duration. Subframe(s) may comprise one or moreslots (e.g. slots 603 and 605) depending on subcarrier spacing and/or CPlength. For example, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz,240 kHz and 480 kHz subcarrier spacing may comprise one, two, four,eight, sixteen and thirty-two slots, respectively. In FIG. 6, a subframemay be divided into two equally sized slots 603 with 0.5 ms duration.For example, 10 subframes may be available for downlink transmission and10 subframes may be available for uplink transmissions in a 10 msinterval. Uplink and downlink transmissions may be separated in thefrequency domain. Slot(s) may include a plurality of OFDM symbols 604.The number of OFDM symbols 604 in a slot 605 may depend on the cyclicprefix length. For example, a slot may be 14 OFDM symbols for the samesubcarrier spacing of up to 480 kHz with normal CP. A slot may be 12OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP.A slot may contain downlink, uplink, or a downlink part and an uplinkpart and/or alike.

FIG. 7A is a diagram depicting example sets of OFDM subcarriers as peran aspect of an embodiment of the present disclosure. In the example, agNB may communicate with a wireless device with a carrier with anexample channel bandwidth 700. Arrow(s) in the diagram may depict asubcarrier in a multicarrier OFDM system. The OFDM system may usetechnology such as OFDM technology, SC-FDMA technology, and/or the like.In an example, an arrow 701 shows a subcarrier transmitting informationsymbols. In an example, a subcarrier spacing 702, between two contiguoussubcarriers in a carrier, may be any one of 15 KHz, 30 KHz, 60 KHz, 120KHz, 240 KHz etc. In an example, different subcarrier spacing maycorrespond to different transmission numerologies. In an example, atransmission numerology may comprise at least: a numerology index; avalue of subcarrier spacing; a type of cyclic prefix (CP). In anexample, a gNB may transmit to/receive from a UE on a number ofsubcarriers 703 in a carrier. In an example, a bandwidth occupied by anumber of subcarriers 703 (transmission bandwidth) may be smaller thanthe channel bandwidth 700 of a carrier, due to guard band 704 and 705.In an example, a guard band 704 and 705 may be used to reduceinterference to and from one or more neighbor carriers. A number ofsubcarriers (transmission bandwidth) in a carrier may depend on thechannel bandwidth of the carrier and the subcarrier spacing. Forexample, a transmission bandwidth, for a carrier with 20 MHz channelbandwidth and 15 KHz subcarrier spacing, may be in number of 1024subcarriers.

In an example, a gNB and a wireless device may communicate with multipleCCs when configured with CA. In an example, different component carriersmay have different bandwidth and/or subcarrier spacing, if CA issupported. In an example, a gNB may transmit a first type of service toa UE on a first component carrier. The gNB may transmit a second type ofservice to the UE on a second component carrier. Different type ofservices may have different service requirement (e.g., data rate,latency, reliability), which may be suitable for transmission viadifferent component carrier having different subcarrier spacing and/orbandwidth. FIG. 7B shows an example embodiment. A first componentcarrier may comprise a first number of subcarriers 706 with a firstsubcarrier spacing 709. A second component carrier may comprise a secondnumber of subcarriers 707 with a second subcarrier spacing 710. A thirdcomponent carrier may comprise a third number of subcarriers 708 with athird subcarrier spacing 711. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 8 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present disclosure. In an example, a carrier mayhave a transmission bandwidth 801. In an example, a resource grid may bein a structure of frequency domain 802 and time domain 803. In anexample, a resource grid may comprise a first number of OFDM symbols ina subframe and a second number of resource blocks, starting from acommon resource block indicated by higher-layer signaling (e.g. RRCsignaling), for a transmission numerology and a carrier. In an example,in a resource grid, a resource unit identified by a subcarrier index anda symbol index may be a resource element 805. In an example, a subframemay comprise a first number of OFDM symbols 807 depending on anumerology associated with a carrier. For example, when a subcarrierspacing of a numerology of a carrier is 15 KHz, a subframe may have 14OFDM symbols for a carrier. When a subcarrier spacing of a numerology is30 KHz, a subframe may have 28 OFDM symbols. When a subcarrier spacingof a numerology is 60 Khz, a subframe may have 56 OFDM symbols, etc. Inan example, a second number of resource blocks comprised in a resourcegrid of a carrier may depend on a bandwidth and a numerology of thecarrier.

As shown in FIG. 8, a resource block 806 may comprise 12 subcarriers. Inan example, multiple resource blocks may be grouped into a ResourceBlock Group (RBG) 804. In an example, a size of a RBG may depend on atleast one of: a RRC message indicating a RBG size configuration; a sizeof a carrier bandwidth; or a size of a bandwidth part of a carrier. Inan example, a carrier may comprise multiple bandwidth parts. A firstbandwidth part of a carrier may have different frequency location and/orbandwidth from a second bandwidth part of the carrier.

In an example, a gNB may transmit a downlink control informationcomprising a downlink or uplink resource block assignment to a wirelessdevice. A base station may transmit to or receive from, a wirelessdevice, data packets (e.g. transport blocks) scheduled and transmittedvia one or more resource blocks and one or more slots according toparameters in a downlink control information and/or RRC message(s). Inan example, a starting symbol relative to a first slot of the one ormore slots may be indicated to the wireless device. In an example, a gNBmay transmit to or receive from, a wireless device, data packetsscheduled on one or more RBGs and one or more slots.

In an example, a gNB may transmit a downlink control informationcomprising a downlink assignment to a wireless device via one or morePDCCHs. The downlink assignment may comprise parameters indicating atleast modulation and coding format; resource allocation; and/or HARQinformation related to DL-SCH. In an example, a resource allocation maycomprise parameters of resource block allocation; and/or slotallocation. In an example, a gNB may dynamically allocate resources to awireless device via a Cell-Radio Network Temporary Identifier (C-RNTI)on one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible allocation when its downlink receptionis enabled. The wireless device may receive one or more downlink datapackage on one or more PDSCH scheduled by the one or more PDCCHs, whensuccessfully detecting the one or more PDCCHs.

In an example, a gNB may allocate Configured Scheduling (CS) resourcesfor down link transmission to a wireless device. The gNB may transmitone or more RRC messages indicating a periodicity of the CS grant. ThegNB may transmit a DCI via a PDCCH addressed to a ConfiguredScheduling-RNTI (CS-RNTI) activating the CS resources. The DCI maycomprise parameters indicating that the downlink grant is a CS grant.The CS grant may be implicitly reused according to the periodicitydefined by the one or more RRC messages, until deactivated.

In an example, a gNB may transmit a downlink control informationcomprising an uplink grant to a wireless device via one or more PDCCHs.The uplink grant may comprise parameters indicating at least modulationand coding format; resource allocation; and/or HARQ information relatedto UL-SCH. In an example, a resource allocation may comprise parametersof resource block allocation; and/or slot allocation. In an example, agNB may dynamically allocate resources to a wireless device via a C-RNTIon one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible resource allocation. The wirelessdevice may transmit one or more uplink data package via one or morePUSCH scheduled by the one or more PDCCHs, when successfully detectingthe one or more PDCCHs.

In an example, a gNB may allocate CS resources for uplink datatransmission to a wireless device. The gNB may transmit one or more RRCmessages indicating a periodicity of the CS grant. The gNB may transmita DCI via a PDCCH addressed to a CS-RNTI activating the CS resources.The DCI may comprise parameters indicating that the uplink grant is a CSgrant. The CS grant may be implicitly reused according to theperiodicity defined by the one or more RRC message, until deactivated.

In an example, a base station may transmit DCI/control signaling viaPDCCH. The DCI may take a format in a plurality of formats. A DCI maycomprise downlink and/or uplink scheduling information (e.g., resourceallocation information, HARQ related parameters, MCS), request for CSI(e.g., aperiodic CQI reports), request for SRS, uplink power controlcommands for one or more cells, one or more timing information (e.g., TBtransmission/reception timing, HARQ feedback timing, etc.), etc. In anexample, a DCI may indicate an uplink grant comprising transmissionparameters for one or more transport blocks. In an example, a DCI mayindicate downlink assignment indicating parameters for receiving one ormore transport blocks. In an example, a DCI may be used by base stationto initiate a contention-free random access at the wireless device. Inan example, the base station may transmit a DCI comprising slot formatindicator (SFI) notifying a slot format. In an example, the base stationmay transmit a DCI comprising pre-emption indication notifying thePRB(s) and/or OFDM symbol(s) where a UE may assume no transmission isintended for the UE. In an example, the base station may transmit a DCIfor group power control of PUCCH or PUSCH or SRS. In an example, a DCImay correspond to an RNTI. In an example, the wireless device may obtainan RNTI in response to completing the initial access (e.g., C-RNTI). Inan example, the base station may configure an RNTI for the wireless(e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI,TPC-SRS-RNTI). In an example, the wireless device may compute an RNTI(e.g., the wireless device may compute RA-RNTI based on resources usedfor transmission of a preamble). In an example, an RNTI may have apre-configured value (e.g., P-RNTI or SI-RNTI). In an example, awireless device may monitor a group common search space which may beused by base station for transmitting DCIs that are intended for a groupof UEs. In an example, a group common DCI may correspond to an RNTIwhich is commonly configured for a group of UEs. In an example, awireless device may monitor a UE-specific search space. In an example, aUE specific DCI may correspond to an RNTI configured for the wirelessdevice.

A NR system may support a single beam operation and/or a multi-beamoperation. In a multi-beam operation, a base station may perform adownlink beam sweeping to provide coverage for common control channelsand/or downlink SS blocks, which may comprise at least a PSS, a SSS,and/or PBCH. A wireless device may measure quality of a beam pair linkusing one or more RSs. One or more SS blocks, or one or more CSI-RSresources, associated with a CSI-RS resource index (CRI), or one or moreDM-RSs of PBCH, may be used as RS for measuring quality of a beam pairlink. Quality of a beam pair link may be defined as a reference signalreceived power (RSRP) value, or a reference signal received quality(RSRQ) value, and/or a CSI value measured on RS resources. The basestation may indicate whether an RS resource, used for measuring a beampair link quality, is quasi-co-located (QCLed) with DM-RSs of a controlchannel. A RS resource and DM-RSs of a control channel may be calledQCLed when a channel characteristics from a transmission on an RS to awireless device, and that from a transmission on a control channel to awireless device, are similar or same under a configured criterion. In amulti-beam operation, a wireless device may perform an uplink beamsweeping to access a cell.

In an example, a wireless device may be configured to monitor PDCCH onone or more beam pair links simultaneously depending on a capability ofa wireless device. This may increase robustness against beam pair linkblocking. A base station may transmit one or more messages to configurea wireless device to monitor PDCCH on one or more beam pair links indifferent PDCCH OFDM symbols. For example, a base station may transmithigher layer signaling (e.g. RRC signaling) or MAC CE comprisingparameters related to the Rx beam setting of a wireless device formonitoring PDCCH on one or more beam pair links. A base station maytransmit indication of spatial QCL assumption between an DL RS antennaport(s) (for example, cell-specific CSI-RS, or wireless device-specificCSI-RS, or SS block, or PBCH with or without DM-RSs of PBCH), and DL RSantenna port(s) for demodulation of DL control channel. Signaling forbeam indication for a PDCCH may be MAC CE signaling, or RRC signaling,or DCI signaling, or specification-transparent and/or implicit method,and combination of these signaling methods.

For reception of unicast DL data channel, a base station may indicatespatial QCL parameters between DL RS antenna port(s) and DM-RS antennaport(s) of DL data channel. The base station may transmit DCI (e.g.downlink grants) comprising information indicating the RS antennaport(s). The information may indicate RS antenna port(s) which may beQCLed with the DM-RS antenna port(s). Different set of DM-RS antennaport(s) for a DL data channel may be indicated as QCL with different setof the RS antenna port(s).

FIG. 9A is an example of beam sweeping in a DL channel. In anRRC_INACTIVE state or RRC_IDLE state, a wireless device may assume thatSS blocks form an SS burst 940, and an SS burst set 950. The SS burstset 950 may have a given periodicity. For example, in a multi-beamoperation, a base station 120 may transmit SS blocks in multiple beams,together forming a SS burst 940. One or more SS blocks may betransmitted on one beam. If multiple SS bursts 940 are transmitted withmultiple beams, SS bursts together may form SS burst set 950.

A wireless device may further use CSI-RS in the multi-beam operation forestimating a beam quality of a links between a wireless device and abase station. A beam may be associated with a CSI-RS. For example, awireless device may, based on a RSRP measurement on CSI-RS, report abeam index, as indicated in a CRI for downlink beam selection, andassociated with a RSRP value of a beam. A CSI-RS may be transmitted on aCSI-RS resource including at least one of one or more antenna ports, oneor more time or frequency radio resources. A CSI-RS resource may beconfigured in a cell-specific way by common RRC signaling, or in awireless device-specific way by dedicated RRC signaling, and/or L1/L2signaling. Multiple wireless devices covered by a cell may measure acell-specific CSI-RS resource. A dedicated subset of wireless devicescovered by a cell may measure a wireless device-specific CSI-RSresource.

A CSI-RS resource may be transmitted periodically, or using aperiodictransmission, or using a multi-shot or semi-persistent transmission. Forexample, in a periodic transmission in FIG. 9A, a base station 120 maytransmit configured CSI-RS resources 940 periodically using a configuredperiodicity in a time domain. In an aperiodic transmission, a configuredCSI-RS resource may be transmitted in a dedicated time slot. In amulti-shot or semi-persistent transmission, a configured CSI-RS resourcemay be transmitted within a configured period. Beams used for CSI-RStransmission may have different beam width than beams used for SS-blockstransmission.

FIG. 9B is an example of a beam management procedure in an example newradio network. A base station 120 and/or a wireless device 110 mayperform a downlink L1/L2 beam management procedure. One or more of thefollowing downlink L1/L2 beam management procedures may be performedwithin one or more wireless devices 110 and one or more base stations120. In an example, a P-1 procedure 910 may be used to enable thewireless device 110 to measure one or more Transmission (Tx) beamsassociated with the base station 120 to support a selection of a firstset of Tx beams associated with the base station 120 and a first set ofRx beam(s) associated with a wireless device 110. For beamforming at abase station 120, a base station 120 may sweep a set of different TXbeams. For beamforming at a wireless device 110, a wireless device 110may sweep a set of different Rx beams. In an example, a P-2 procedure920 may be used to enable a wireless device 110 to measure one or moreTx beams associated with a base station 120 to possibly change a firstset of Tx beams associated with a base station 120. A P-2 procedure 920may be performed on a possibly smaller set of beams for beam refinementthan in the P-1 procedure 910. A P-2 procedure 920 may be a special caseof a P-1 procedure 910. In an example, a P-3 procedure 930 may be usedto enable a wireless device 110 to measure at least one Tx beamassociated with a base station 120 to change a first set of Rx beamsassociated with a wireless device 110.

A wireless device 110 may transmit one or more beam management reportsto a base station 120. In one or more beam management reports, awireless device 110 may indicate some beam pair quality parameters,comprising at least, one or more beam identifications; RSRP; PrecodingMatrix Indicator (PMI)/Channel Quality Indicator (CQI)/Rank Indicator(RI) of a subset of configured beams. Based on one or more beammanagement reports, a base station 120 may transmit to a wireless device110 a signal indicating that one or more beam pair links are one or moreserving beams. A base station 120 may transmit PDCCH and PDSCH for awireless device 110 using one or more serving beams.

In an example embodiment, new radio network may support a BandwidthAdaptation (BA). In an example, receive and/or transmit bandwidthsconfigured by an UE employing a BA may not be large. For example, areceive and/or transmit bandwidths may not be as large as a bandwidth ofa cell. Receive and/or transmit bandwidths may be adjustable. Forexample, a UE may change receive and/or transmit bandwidths, e.g., toshrink during period of low activity to save power. For example, a UEmay change a location of receive and/or transmit bandwidths in afrequency domain, e.g. to increase scheduling flexibility. For example,a UE may change a subcarrier spacing, e.g. to allow different services.

In an example embodiment, a subset of a total cell bandwidth of a cellmay be referred to as a Bandwidth Part (BWP). A base station mayconfigure a UE with one or more BWPs to achieve a BA. For example, abase station may indicate, to a UE, which of the one or more(configured) BWPs is an active BWP.

FIG. 10 is an example diagram of 3 BWPs configured: BWP1 (1010 and 1050)with a width of 40 MHz and subcarrier spacing of 15 kHz; BWP2 (1020 and1040) with a width of 10 MHz and subcarrier spacing of 15 kHz; BWP3 1030with a width of 20 MHz and subcarrier spacing of 60 kHz.

In an example, a UE, configured for operation in one or more BWPs of acell, may be configured by one or more higher layers (e.g. RRC layer)for a cell a set of one or more BWPs (e.g., at most four BWPs) forreceptions by the UE (DL BWP set) in a DL bandwidth by at least oneparameter DL-BWP and a set of one or more BWPs (e.g., at most four BWPs)for transmissions by a UE (UL BWP set) in an UL bandwidth by at leastone parameter UL-BWP for a cell.

To enable BA on the PCell, a base station may configure a UE with one ormore UL and DL BWP pairs. To enable BA on SCells (e.g., in case of CA),a base station may configure a UE at least with one or more DL BWPs(e.g., there may be none in an UL).

In an example, an initial active DL BWP may be defined by at least oneof a location and number of contiguous PRBs, a subcarrier spacing, or acyclic prefix, for a control resource set for at least one common searchspace. For operation on the PCell, one or more higher layer parametersmay indicate at least one initial UL BWP for a random access procedure.If a UE is configured with a secondary carrier on a primary cell, the UEmay be configured with an initial BWP for random access procedure on asecondary carrier.

In an example, for unpaired spectrum operation, a UE may expect that acenter frequency for a DL BWP may be same as a center frequency for a ULBWP.

For example, for a DL BWP or an UL BWP in a set of one or more DL BWPsor one or more UL BWPs, respectively, a base station maysemi-statistically configure a UE for a cell with one or more parametersindicating at least one of following: a subcarrier spacing; a cyclicprefix; a number of contiguous PRBs; an index in the set of one or moreDL BWPs and/or one or more UL BWPs; a link between a DL BWP and an ULBWP from a set of configured DL BWPs and UL BWPs; a DCI detection to aPDSCH reception timing; a PDSCH reception to a HARQ-ACK transmissiontiming value; a DCI detection to a PUSCH transmission timing value; anoffset of a first PRB of a DL bandwidth or an UL bandwidth,respectively, relative to a first PRB of a bandwidth.

In an example, for a DL BWP in a set of one or more DL BWPs on a PCell,a base station may configure a UE with one or more control resource setsfor at least one type of common search space and/or one UE-specificsearch space. For example, a base station may not configure a UE withouta common search space on a PCell, or on a PSCell, in an active DL BWP.

For an UL BWP in a set of one or more UL BWPs, a base station mayconfigure a UE with one or more resource sets for one or more PUCCHtransmissions.

In an example, if a DCI comprises a BWP indicator field, a BWP indicatorfield value may indicate an active DL BWP, from a configured DL BWP set,for one or more DL receptions. If a DCI comprises a BWP indicator field,a BWP indicator field value may indicate an active UL BWP, from aconfigured UL BWP set, for one or more UL transmissions.

In an example, for a PCell, a base station may semi-statisticallyconfigure a UE with a default DL BWP among configured DL BWPs. If a UEis not provided a default DL BWP, a default BWP may be an initial activeDL BWP.

In an example, a base station may configure a UE with a timer value fora PCell. For example, a UE may start a timer, referred to as BWPinactivity timer, when a UE detects a DCI indicating an active DL BWP,other than a default DL BWP, for a paired spectrum operation or when aUE detects a DCI indicating an active DL BWP or UL BWP, other than adefault DL BWP or UL BWP, for an unpaired spectrum operation. The UE mayincrement the timer by an interval of a first value (e.g., the firstvalue may be 1 millisecond or 0.5 milliseconds) if the UE does notdetect a DCI during the interval for a paired spectrum operation or foran unpaired spectrum operation. In an example, the timer may expire whenthe timer is equal to the timer value. A UE may switch to the default DLBWP from an active DL BWP when the timer expires.

In an example, a base station may semi-statistically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of BWP inactivity timer(for example, the second BWP may be a default BWP). For example, FIG. 10is an example diagram of 3 BWPs configured, BWP1 (1010 and 1050), BWP2(1020 and 1040), and BWP3 (1030). BWP2 (1020 and 1040) may be a defaultBWP. BWP1 (1010) may be an initial active BWP. In an example, a UE mayswitch an active BWP from BWP1 1010 to BWP2 1020 in response to anexpiry of BWP inactivity timer. For example, a UE may switch an activeBWP from BWP2 1020 to BWP3 1030 in response to receiving a DCIindicating BWP3 1030 as an active BWP. Switching an active BWP from BWP31030 to BWP2 1040 and/or from BWP2 1040 to BWP1 1050 may be in responseto receiving a DCI indicating an active BWP and/or in response to anexpiry of BWP inactivity timer.

In an example, if a UE is configured for a secondary cell with a defaultDL BWP among configured DL BWPs and a timer value, UE procedures on asecondary cell may be same as on a primary cell using the timer valuefor the secondary cell and the default DL BWP for the secondary cell.

In an example, if a base station configures a UE with a first active DLBWP and a first active UL BWP on a secondary cell or carrier, a UE mayemploy an indicated DL BWP and an indicated UL BWP on a secondary cellas a respective first active DL BWP and first active UL BWP on asecondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows employing a multi connectivity(e.g. dual connectivity, multi connectivity, tight interworking, and/orthe like). FIG. 11A is an example diagram of a protocol structure of awireless device 110 (e.g. UE) with CA and/or multi connectivity as peran aspect of an embodiment. FIG. 11B is an example diagram of a protocolstructure of multiple base stations with CA and/or multi connectivity asper an aspect of an embodiment. The multiple base stations may comprisea master node, MN 1130 (e.g. a master node, a master base station, amaster gNB, a master eNB, and/or the like) and a secondary node, SN 1150(e.g. a secondary node, a secondary base station, a secondary gNB, asecondary eNB, and/or the like). A master node 1130 and a secondary node1150 may co-work to communicate with a wireless device 110.

When multi connectivity is configured for a wireless device 110, thewireless device 110, which may support multiple reception/transmissionfunctions in an RRC connected state, may be configured to utilize radioresources provided by multiple schedulers of a multiple base stations.Multiple base stations may be inter-connected via a non-ideal or idealbackhaul (e.g. Xn interface, X2 interface, and/or the like). A basestation involved in multi connectivity for a certain wireless device mayperform at least one of two different roles: a base station may eitheract as a master base station or as a secondary base station. In multiconnectivity, a wireless device may be connected to one master basestation and one or more secondary base stations. In an example, a masterbase station (e.g. the MN 1130) may provide a master cell group (MCG)comprising a primary cell and/or one or more secondary cells for awireless device (e.g. the wireless device 110). A secondary base station(e.g. the SN 1150) may provide a secondary cell group (SCG) comprising aprimary secondary cell (PSCell) and/or one or more secondary cells for awireless device (e.g. the wireless device 110).

In multi connectivity, a radio protocol architecture that a beareremploys may depend on how a bearer is setup. In an example, threedifferent type of bearer setup options may be supported: an MCG bearer,an SCG bearer, and/or a split bearer. A wireless device mayreceive/transmit packets of an MCG bearer via one or more cells of theMCG, and/or may receive/transmits packets of an SCG bearer via one ormore cells of an SCG. Multi-connectivity may also be described as havingat least one bearer configured to use radio resources provided by thesecondary base station. Multi-connectivity may or may not beconfigured/implemented in some of the example embodiments.

In an example, a wireless device (e.g. Wireless Device 110) may transmitand/or receive: packets of an MCG bearer via an SDAP layer (e.g. SDAP1110), a PDCP layer (e.g. NR PDCP 1111), an RLC layer (e.g. MN RLC1114), and a MAC layer (e.g. MN MAC 1118); packets of a split bearer viaan SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1112), one ofa master or secondary RLC layer (e.g. MN RLC 1115, SN RLC 1116), and oneof a master or secondary MAC layer (e.g. MN MAC 1118, SN MAC 1119);and/or packets of an SCG bearer via an SDAP layer (e.g. SDAP 1110), aPDCP layer (e.g. NR PDCP 1113), an RLC layer (e.g. SN RLC 1117), and aMAC layer (e.g. MN MAC 1119).

In an example, a master base station (e.g. MN 1130) and/or a secondarybase station (e.g. SN 1150) may transmit/receive: packets of an MCGbearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g. NR PDCP 1121, NR PDCP1142), a master node RLC layer (e.g. MN RLC 1124, MN RLC 1125), and amaster node MAC layer (e.g. MN MAC 1128); packets of an SCG bearer via amaster or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1122, NR PDCP 1143), asecondary node RLC layer (e.g. SN RLC 1146, SN RLC 1147), and asecondary node MAC layer (e.g. SN MAC 1148); packets of a split bearervia a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1123, NR PDCP 1141), amaster or secondary node RLC layer (e.g. MN RLC 1126, SN RLC 1144, SNRLC 1145, MN RLC 1127), and a master or secondary node MAC layer (e.g.MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MACentities: one MAC entity (e.g. MN MAC 1118) for a master base station,and other MAC entities (e.g. SN MAC 1119) for a secondary base station.In multi-connectivity, a configured set of serving cells for a wirelessdevice may comprise two subsets: an MCG comprising serving cells of amaster base station, and SCGs comprising serving cells of a secondarybase station. For an SCG, one or more of following configurations may beapplied: at least one cell of an SCG has a configured UL CC and at leastone cell of a SCG, named as primary secondary cell (PSCell, PCell ofSCG, or sometimes called PCell), is configured with PUCCH resources;when an SCG is configured, there may be at least one SCG bearer or oneSplit bearer; upon detection of a physical layer problem or a randomaccess problem on a PSCell, or a number of NR RLC retransmissions hasbeen reached associated with the SCG, or upon detection of an accessproblem on a PSCell during a SCG addition or a SCG change: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of an SCG may be stopped, a master basestation may be informed by a wireless device of a SCG failure type, forsplit bearer, a DL data transfer over a master base station may bemaintained; an NR RLC acknowledged mode (AM) bearer may be configuredfor a split bearer; PCell and/or PSCell may not be de-activated; PSCellmay be changed with a SCG change procedure (e.g. with security keychange and a RACH procedure); and/or a bearer type change between asplit bearer and a SCG bearer or simultaneous configuration of a SCG anda split bearer may or may not supported.

With respect to interaction between a master base station and asecondary base stations for multi-connectivity, one or more of thefollowing may be applied: a master base station and/or a secondary basestation may maintain RRM measurement configurations of a wirelessdevice; a master base station may (e.g. based on received measurementreports, traffic conditions, and/or bearer types) may decide to requesta secondary base station to provide additional resources (e.g. servingcells) for a wireless device; upon receiving a request from a masterbase station, a secondary base station may create/modify a containerthat may result in configuration of additional serving cells for awireless device (or decide that the secondary base station has noresource available to do so); for a UE capability coordination, a masterbase station may provide (a part of) an AS configuration and UEcapabilities to a secondary base station; a master base station and asecondary base station may exchange information about a UE configurationby employing of RRC containers (inter-node messages) carried via Xnmessages; a secondary base station may initiate a reconfiguration of thesecondary base station existing serving cells (e.g. PUCCH towards thesecondary base station); a secondary base station may decide which cellis a PSCell within a SCG; a master base station may or may not changecontent of RRC configurations provided by a secondary base station; incase of a SCG addition and/or a SCG SCell addition, a master basestation may provide recent (or the latest) measurement results for SCGcell(s); a master base station and secondary base stations may receiveinformation of SFN and/or subframe offset of each other from OAM and/orvia an Xn interface, (e.g. for a purpose of DRX alignment and/oridentification of a measurement gap). In an example, when adding a newSCG SCell, dedicated RRC signaling may be used for sending requiredsystem information of a cell as for CA, except for a SFN acquired from aMIB of a PSCell of a SCG.

FIG. 12 is an example diagram of a random access procedure. One or moreevents may trigger a random access procedure. For example, one or moreevents may be at least one of following: initial access from RRC_IDLE,RRC connection re-establishment procedure, handover, DL or UL dataarrival during RRC_CONNECTED when UL synchronization status isnon-synchronised, transition from RRC_Inactive, and/or request for othersystem information. For example, a PDCCH order, a MAC entity, and/or abeam failure indication may initiate a random access procedure.

In an example embodiment, a random access procedure may be at least oneof a contention based random access procedure and a contention freerandom access procedure. For example, a contention based random accessprocedure may comprise, one or more Msg 1 1220 transmissions, one ormore Msg2 1230 transmissions, one or more Msg3 1240 transmissions, andcontention resolution 1250. For example, a contention free random accessprocedure may comprise one or more Msg 1 1220 transmissions and one ormore Msg2 1230 transmissions.

In an example, a base station may transmit (e.g., unicast, multicast, orbroadcast), to a UE, a RACH configuration 1210 via one or more beams.The RACH configuration 1210 may comprise one or more parametersindicating at least one of following: available set of PRACH resourcesfor a transmission of a random access preamble, initial preamble power(e.g., random access preamble initial received target power), an RSRPthreshold for a selection of a SS block and corresponding PRACHresource, a power-ramping factor (e.g., random access preamble powerramping step), random access preamble index, a maximum number ofpreamble transmission, preamble group A and group B, a threshold (e.g.,message size) to determine the groups of random access preambles, a setof one or more random access preambles for system information requestand corresponding PRACH resource(s), if any, a set of one or more randomaccess preambles for beam failure recovery request and correspondingPRACH resource(s), if any, a time window to monitor RA response(s), atime window to monitor response(s) on beam failure recovery request,and/or a contention resolution timer.

In an example, the Msg1 1220 may be one or more transmissions of arandom access preamble. For a contention based random access procedure,a UE may select a SS block with a RSRP above the RSRP threshold. Ifrandom access preambles group B exists, a UE may select one or morerandom access preambles from a group A or a group B depending on apotential Msg3 1240 size. If a random access preambles group B does notexist, a UE may select the one or more random access preambles from agroup A. A UE may select a random access preamble index randomly (e.g.with equal probability or a normal distribution) from one or more randomaccess preambles associated with a selected group. If a base stationsemi-statistically configures a UE with an association between randomaccess preambles and SS blocks, the UE may select a random accesspreamble index randomly with equal probability from one or more randomaccess preambles associated with a selected SS block and a selectedgroup.

For example, a UE may initiate a contention free random access procedurebased on a beam failure indication from a lower layer. For example, abase station may semi-statistically configure a UE with one or morecontention free PRACH resources for beam failure recovery requestassociated with at least one of SS blocks and/or CSI-RSs. If at leastone of SS blocks with a RSRP above a first RSRP threshold amongstassociated SS blocks or at least one of CSI-RSs with a RSRP above asecond RSRP threshold amongst associated CSI-RSs is available, a UE mayselect a random access preamble index corresponding to a selected SSblock or CSI-RS from a set of one or more random access preambles forbeam failure recovery request.

For example, a UE may receive, from a base station, a random accesspreamble index via PDCCH or RRC for a contention free random accessprocedure. If a base station does not configure a UE with at least onecontention free PRACH resource associated with SS blocks or CSI-RS, theUE may select a random access preamble index. If a base stationconfigures a UE with one or more contention free PRACH resourcesassociated with SS blocks and at least one SS block with a RSRP above afirst RSRP threshold amongst associated SS blocks is available, the UEmay select the at least one SS block and select a random access preamblecorresponding to the at least one SS block. If a base station configuresa UE with one or more contention free PRACH resources associated withCSI-RSs and at least one CSI-RS with a RSRP above a second RSPRthreshold amongst the associated CSI-RSs is available, the UE may selectthe at least one CSI-RS and select a random access preamblecorresponding to the at least one CSI-RS.

A UE may perform one or more Msg1 1220 transmissions by transmitting theselected random access preamble. For example, if a UE selects an SSblock and is configured with an association between one or more PRACHoccasions and one or more SS blocks, the UE may determine an PRACHoccasion from one or more PRACH occasions corresponding to a selected SSblock. For example, if a UE selects a CSI-RS and is configured with anassociation between one or more PRACH occasions and one or more CSI-RSs,the UE may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected CSI-RS. A UE may transmit, to a basestation, a selected random access preamble via a selected PRACHoccasions. A UE may determine a transmit power for a transmission of aselected random access preamble at least based on an initial preamblepower and a power-ramping factor. A UE may determine a RA-RNTIassociated with a selected PRACH occasions in which a selected randomaccess preamble is transmitted. For example, a UE may not determine aRA-RNTI for a beam failure recovery request. A UE may determine anRA-RNTI at least based on an index of a first OFDM symbol and an indexof a first slot of a selected PRACH occasions, and/or an uplink carrierindex for a transmission of Msg1 1220.

In an example, a UE may receive, from a base station, a random accessresponse, Msg 2 1230. A UE may start a time window (e.g.,ra-ResponseWindow) to monitor a random access response. For beam failurerecovery request, a base station may configure a UE with a differenttime window (e.g., bfr-ResponseWindow) to monitor response on beamfailure recovery request. For example, a UE may start a time window(e.g., ra-ResponseWindow or bfr-ResponseWindow) at a start of a firstPDCCH occasion after a fixed duration of one or more symbols from an endof a preamble transmission. If a UE transmits multiple preambles, the UEmay start a time window at a start of a first PDCCH occasion after afixed duration of one or more symbols from an end of a first preambletransmission. A UE may monitor a PDCCH of a cell for at least one randomaccess response identified by a RA-RNTI or for at least one response tobeam failure recovery request identified by a C-RNTI while a timer for atime window is running.

In an example, a UE may consider a reception of random access responsesuccessful if at least one random access response comprises a randomaccess preamble identifier corresponding to a random access preambletransmitted by the UE. A UE may consider the contention free randomaccess procedure successfully completed if a reception of random accessresponse is successful. If a contention free random access procedure istriggered for a beam failure recovery request, a UE may consider acontention free random access procedure successfully complete if a PDCCHtransmission is addressed to a C-RNTI. In an example, if at least onerandom access response comprises a random access preamble identifier, aUE may consider the random access procedure successfully completed andmay indicate a reception of an acknowledgement for a system informationrequest to upper layers. If a UE has signaled multiple preambletransmissions, the UE may stop transmitting remaining preambles (if any)in response to a successful reception of a corresponding random accessresponse.

In an example, a UE may perform one or more Msg 3 1240 transmissions inresponse to a successful reception of random access response (e.g., fora contention based random access procedure). A UE may adjust an uplinktransmission timing based on a timing advanced command indicated by arandom access response and may transmit one or more transport blocksbased on an uplink grant indicated by a random access response.Subcarrier spacing for PUSCH transmission for Msg3 1240 may be providedby at least one higher layer (e.g. RRC) parameter. A UE may transmit arandom access preamble via PRACH and Msg3 1240 via PUSCH on a same cell.A base station may indicate an UL BWP for a PUSCH transmission of Msg31240 via system information block. A UE may employ HARQ for aretransmission of Msg 3 1240.

In an example, multiple UEs may perform Msg 1 1220 by transmitting asame preamble to a base station and receive, from the base station, asame random access response comprising an identity (e.g., TC-RNTI).Contention resolution 1250 may ensure that a UE does not incorrectly usean identity of another UE. For example, contention resolution 1250 maybe based on C-RNTI on PDCCH or a UE contention resolution identity onDL-SCH. For example, if a base station assigns a C-RNTI to a UE, the UEmay perform contention resolution 1250 based on a reception of a PDCCHtransmission that is addressed to the C-RNTI. In response to detectionof a C-RNTI on a PDCCH, a UE may consider contention resolution 1250successful and may consider a random access procedure successfullycompleted. If a UE has no valid C-RNTI, a contention resolution may beaddressed by employing a TC-RNTI. For example, if a MAC PDU issuccessfully decoded and a MAC PDU comprises a UE contention resolutionidentity MAC CE that matches the CCCH SDU transmitted in Msg3 1250, a UEmay consider the contention resolution 1250 successful and may considerthe random access procedure successfully completed.

FIG. 13 is an example structure for MAC entities as per an aspect of anembodiment. In an example, a wireless device may be configured tooperate in a multi-connectivity mode. A wireless device in RRC_CONNECTEDwith multiple RX/TX may be configured to utilize radio resourcesprovided by multiple schedulers located in a plurality of base stations.The plurality of base stations may be connected via a non-ideal or idealbackhaul over the Xn interface. In an example, a base station in aplurality of base stations may act as a master base station or as asecondary base station. A wireless device may be connected to one masterbase station and one or more secondary base stations. A wireless devicemay be configured with multiple MAC entities, e.g. one MAC entity formaster base station, and one or more other MAC entities for secondarybase station(s). In an example, a configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and one or more SCGs comprising servingcells of a secondary base station(s). FIG. 13 illustrates an examplestructure for MAC entities when MCG and SCG are configured for awireless device.

In an example, at least one cell in a SCG may have a configured UL CC,wherein a cell of at least one cell may be called PSCell or PCell ofSCG, or sometimes may be simply called PCell. A PSCell may be configuredwith PUCCH resources. In an example, when a SCG is configured, there maybe at least one SCG bearer or one split bearer. In an example, upondetection of a physical layer problem or a random access problem on aPSCell, or upon reaching a number of RLC retransmissions associated withthe SCG, or upon detection of an access problem on a PSCell during a SCGaddition or a SCG change: an RRC connection re-establishment proceduremay not be triggered, UL transmissions towards cells of an SCG may bestopped, a master base station may be informed by a UE of a SCG failuretype and DL data transfer over a master base station may be maintained.

In an example, a MAC sublayer may provide services such as data transferand radio resource allocation to upper layers (e.g. 1310 or 1320). A MACsublayer may comprise a plurality of MAC entities (e.g. 1350 and 1360).A MAC sublayer may provide data transfer services on logical channels.To accommodate different kinds of data transfer services, multiple typesof logical channels may be defined. A logical channel may supporttransfer of a particular type of information. A logical channel type maybe defined by what type of information (e.g., control or data) istransferred. For example, BCCH, PCCH, CCCH and DCCH may be controlchannels and DTCH may be a traffic channel. In an example, a first MACentity (e.g. 1310) may provide services on PCCH, BCCH, CCCH, DCCH, DTCHand MAC control elements. In an example, a second MAC entity (e.g. 1320)may provide services on BCCH, DCCH, DTCH and MAC control elements.

A MAC sublayer may expect from a physical layer (e.g. 1330 or 1340)services such as data transfer services, signaling of HARQ feedback,signaling of scheduling request or measurements (e.g. CQI). In anexample, in dual connectivity, two MAC entities may be configured for awireless device: one for MCG and one for SCG. A MAC entity of wirelessdevice may handle a plurality of transport channels. In an example, afirst MAC entity may handle first transport channels comprising a PCCHof MCG, a first BCH of MCG, one or more first DL-SCHs of MCG, one ormore first UL-SCHs of MCG and one or more first RACHs of MCG. In anexample, a second MAC entity may handle second transport channelscomprising a second BCH of SCG, one or more second DL-SCHs of SCG, oneor more second UL-SCHs of SCG and one or more second RACHs of SCG.

In an example, if a MAC entity is configured with one or more SCells,there may be multiple DL-SCHs and there may be multiple UL-SCHs as wellas multiple RACHs per MAC entity. In an example, there may be one DL-SCHand UL-SCH on a SpCell. In an example, there may be one DL-SCH, zero orone UL-SCH and zero or one RACH for an SCell. A DL-SCH may supportreceptions using different numerologies and/or TTI duration within a MACentity. A UL-SCH may also support transmissions using differentnumerologies and/or TTI duration within the MAC entity.

In an example, a MAC sublayer may support different functions and maycontrol these functions with a control (e.g. 1355 or 1365) element.Functions performed by a MAC entity may comprise mapping between logicalchannels and transport channels (e.g., in uplink or downlink),multiplexing (e.g. 1352 or 1362) of MAC SDUs from one or differentlogical channels onto transport blocks (TB) to be delivered to thephysical layer on transport channels (e.g., in uplink), demultiplexing(e.g. 1352 or 1362) of MAC SDUs to one or different logical channelsfrom transport blocks (TB) delivered from the physical layer ontransport channels (e.g., in downlink), scheduling information reporting(e.g., in uplink), error correction through HARQ in uplink or downlink(e.g. 1363), and logical channel prioritization in uplink (e.g. 1351 or1361). A MAC entity may handle a random access process (e.g. 1354 or1364).

FIG. 14 is an example diagram of a RAN architecture comprising one ormore base stations. In an example, a protocol stack (e.g. RRC, SDAP,PDCP, RLC, MAC, and PHY) may be supported at a node. A base station(e.g. gNB 120A or 120B) may comprise a base station central unit (CU)(e.g. gNB-CU 1420A or 1420B) and at least one base station distributedunit (DU) (e.g. gNB-DU 1430A, 1430B, 1430C, or 1430D) if a functionalsplit is configured. Upper protocol layers of a base station may belocated in a base station CU, and lower layers of the base station maybe located in the base station DUs. An F1 interface (e.g. CU-DUinterface) connecting a base station CU and base station DUs may be anideal or non-ideal backhaul. F1-C may provide a control plane connectionover an F1 interface, and F1-U may provide a user plane connection overthe F1 interface. In an example, an Xn interface may be configuredbetween base station CUs.

In an example, a base station CU may comprise an RRC function, an SDAPlayer, and a PDCP layer, and base station DUs may comprise an RLC layer,a MAC layer, and a PHY layer. In an example, various functional splitoptions between a base station CU and base station DUs may be possibleby locating different combinations of upper protocol layers (RANfunctions) in a base station CU and different combinations of lowerprotocol layers (RAN functions) in base station DUs. A functional splitmay support flexibility to move protocol layers between a base stationCU and base station DUs depending on service requirements and/or networkenvironments.

In an example, functional split options may be configured per basestation, per base station CU, per base station DU, per UE, per bearer,per slice, or with other granularities. In per base station CU split, abase station CU may have a fixed split option, and base station DUs maybe configured to match a split option of a base station CU. In per basestation DU split, a base station DU may be configured with a differentsplit option, and a base station CU may provide different split optionsfor different base station DUs. In per UE split, a base station (basestation CU and at least one base station DUs) may provide differentsplit options for different wireless devices. In per bearer split,different split options may be utilized for different bearers. In perslice splice, different split options may be applied for differentslices.

FIG. 15 is an example diagram showing RRC state transitions of awireless device. In an example, a wireless device may be in at least oneRRC state among an RRC connected state (e.g. RRC Connected 1530,RRC_Connected), an RRC idle state (e.g. RRC Idle 1510, RRC_Idle), and/oran RRC inactive state (e.g. RRC Inactive 1520, RRC_Inactive). In anexample, in an RRC connected state, a wireless device may have at leastone RRC connection with at least one base station (e.g. gNB and/or eNB),which may have a UE context of the wireless device. A UE context (e.g. awireless device context) may comprise at least one of an access stratumcontext, one or more radio link configuration parameters, bearer (e.g.data radio bearer (DRB), signaling radio bearer (SRB), logical channel,QoS flow, PDU session, and/or the like) configuration information,security information, PHY/MAC/RLC/PDCP/SDAP layer configurationinformation, and/or the like configuration information for a wirelessdevice. In an example, in an RRC idle state, a wireless device may nothave an RRC connection with a base station, and a UE context of awireless device may not be stored in a base station. In an example, inan RRC inactive state, a wireless device may not have an RRC connectionwith a base station. A UE context of a wireless device may be stored ina base station, which may be called as an anchor base station (e.g. lastserving base station).

In an example, a wireless device may transition a UE RRC state betweenan RRC idle state and an RRC connected state in both ways (e.g.connection release 1540 or connection establishment 1550; or connectionreestablishment) and/or between an RRC inactive state and an RRCconnected state in both ways (e.g. connection inactivation 1570 orconnection resume 1580). In an example, a wireless device may transitionits RRC state from an RRC inactive state to an RRC idle state (e.g.connection release 1560).

In an example, an anchor base station may be a base station that maykeep a UE context (a wireless device context) of a wireless device atleast during a time period that a wireless device stays in a RANnotification area (RNA) of an anchor base station, and/or that awireless device stays in an RRC inactive state. In an example, an anchorbase station may be a base station that a wireless device in an RRCinactive state was lastly connected to in a latest RRC connected stateor that a wireless device lastly performed an RNA update procedure in.In an example, an RNA may comprise one or more cells operated by one ormore base stations. In an example, a base station may belong to one ormore RNAs. In an example, a cell may belong to one or more RNAs.

In an example, a wireless device may transition a UE RRC state from anRRC connected state to an RRC inactive state in a base station. Awireless device may receive RNA information from the base station. RNAinformation may comprise at least one of an RNA identifier, one or morecell identifiers of one or more cells of an RNA, a base stationidentifier, an IP address of the base station, an AS context identifierof the wireless device, a resume identifier, and/or the like.

In an example, an anchor base station may broadcast a message (e.g. RANpaging message) to base stations of an RNA to reach to a wireless devicein an RRC inactive state, and/or the base stations receiving the messagefrom the anchor base station may broadcast and/or multicast anothermessage (e.g. paging message) to wireless devices in their coveragearea, cell coverage area, and/or beam coverage area associated with theRNA through an air interface.

In an example, when a wireless device in an RRC inactive state movesinto a new RNA, the wireless device may perform an RNA update (RNAU)procedure, which may comprise a random access procedure by the wirelessdevice and/or a UE context retrieve procedure. A UE context retrieve maycomprise: receiving, by a base station from a wireless device, a randomaccess preamble; and fetching, by a base station, a UE context of thewireless device from an old anchor base station. Fetching may comprise:sending a retrieve UE context request message comprising a resumeidentifier to the old anchor base station and receiving a retrieve UEcontext response message comprising the UE context of the wirelessdevice from the old anchor base station.

In an example embodiment, a wireless device in an RRC inactive state mayselect a cell to camp on based on at least a on measurement results forone or more cells, a cell where a wireless device may monitor an RNApaging message and/or a core network paging message from a base station.In an example, a wireless device in an RRC inactive state may select acell to perform a random access procedure to resume an RRC connectionand/or to transmit one or more packets to a base station (e.g. to anetwork). In an example, if a cell selected belongs to a different RNAfrom an RNA for a wireless device in an RRC inactive state, the wirelessdevice may initiate a random access procedure to perform an RNA updateprocedure. In an example, if a wireless device in an RRC inactive statehas one or more packets, in a buffer, to transmit to a network, thewireless device may initiate a random access procedure to transmit oneor more packets to a base station of a cell that the wireless deviceselects. A random access procedure may be performed with two messages(e.g. 2 stage random access) and/or four messages (e.g. 4 stage randomaccess) between the wireless device and the base station.

In an example embodiment, a base station receiving one or more uplinkpackets from a wireless device in an RRC inactive state may fetch a UEcontext of a wireless device by transmitting a retrieve UE contextrequest message for the wireless device to an anchor base station of thewireless device based on at least one of an AS context identifier, anRNA identifier, a base station identifier, a resume identifier, and/or acell identifier received from the wireless device. In response tofetching a UE context, a base station may transmit a path switch requestfor a wireless device to a core network entity (e.g. AMF, MME, and/orthe like). A core network entity may update a downlink tunnel endpointidentifier for one or more bearers established for the wireless devicebetween a user plane core network entity (e.g. UPF, S-GW, and/or thelike) and a RAN node (e.g. the base station), e.g. changing a downlinktunnel endpoint identifier from an address of the anchor base station toan address of the base station.

A gNB may communicate with a wireless device via a wireless networkemploying one or more new radio technologies. The one or more radiotechnologies may comprise at least one of: multiple technologies relatedto physical layer; multiple technologies related to medium accesscontrol layer; and/or multiple technologies related to radio resourcecontrol layer. Example embodiments of enhancing the one or more radiotechnologies may improve performance of a wireless network. Exampleembodiments may increase the system throughput, or data rate oftransmission. Example embodiments may reduce battery consumption of awireless device. Example embodiments may improve latency of datatransmission between a gNB and a wireless device. Example embodimentsmay improve network coverage of a wireless network. Example embodimentsmay improve transmission efficiency of a wireless network.

Example Downlink Control Information (DCI)

In an example, a gNB may transmit a DCI via a PDCCH for at least one of:scheduling assignment/grant; slot format notification; pre-emptionindication; and/or power-control commends. More specifically, the DCImay comprise at least one of: identifier of a DCI format; downlinkscheduling assignment(s); uplink scheduling grant(s); slot formatindicator; pre-emption indication; power-control for PUCCH/PUSCH; and/orpower-control for SRS.

In an example, a downlink scheduling assignment DCI may compriseparameters indicating at least one of: identifier of a DCI format; PDSCHresource indication; transport format; HARQ information; controlinformation related to multiple antenna schemes; and/or a command forpower control of the PUCCH.

In an example, an uplink scheduling grant DCI may comprise parametersindicating at least one of: identifier of a DCI format; PUSCH resourceindication; transport format; HARQ related information; and/or a powercontrol command of the PUSCH.

In an example, a wireless device may monitor one or more PDCCH fordetecting one or more DCI with one or more DCI format, in common searchspace or wireless device-specific search space. In an example, awireless device may monitor PDCCH with a limited set of DCI format, tosave power consumption. The more DCI format to be detected, the morepower be consumed at the wireless device.

In an example, the information in the DCI formats for downlinkscheduling may comprise at least one of: identifier of a DCI format;carrier indicator; frequency domain resource assignment; time domainresource assignment; bandwidth part indicator; HARQ process number; oneor more MCS; one or more NDI; one or more RV; MIMO related information;Downlink assignment index (DAI); PUCCH resource indicator;PDSCH-to-HARQ_feedback timing indicator; TPC for PUCCH; SRS request; andpadding if necessary. In an example, the MIMO related information maycomprise at least one of: PMI; precoding information; transport blockswap flag; power offset between PDSCH and reference signal;reference-signal scrambling sequence; number of layers; and/or antennaports for the transmission; and/or Transmission Configuration Indication(TCI).

In an example, the information in the DCI formats used for uplinkscheduling may comprise at least one of: an identifier of a DCI format;carrier indicator; bandwidth part indication; resource allocation type;frequency domain resource assignment; time domain resource assignment;MCS; NDI; Phase rotation of the uplink DMRS; precoding information; CSIrequest; SRS request; Uplink index/DAI; TPC for PUSCH; and/or padding ifnecessary.

In an example, a gNB may perform CRC scrambling for a DCI, beforetransmitting the DCI via a PDCCH. The gNB may perform CRC scrambling bybinary addition of multiple bits of at least one wireless deviceidentifier (e.g., C-RNTI, CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI,TPC-PUSCH-RNTI, SP CSI C-RNTI, or TPC-SRS-RNTI) and the CRC bits of theDCI. The wireless device may check the CRC bits of the DCI, whendetecting the DCI. The wireless device may receive the DCI when the CRCis scrambled by a sequence of bits that is the same as the at least onewireless device identifier.

In an example, in order to support wide bandwidth operation, a gNB maytransmit one or more PDCCH in different control resource sets(coresets). A gNB may transmit one or more RRC message comprisingconfiguration parameters of one or more coresets. A coreset may compriseat least one of: a first OFDM symbol; a number of consecutive OFDMsymbols; a set of resource blocks; a CCE-to-REG mapping. In an example,a gNB may transmit a PDCCH in a dedicated coreset for particularpurpose, for example, for beam failure recovery confirmation.

Example of 2-Step RACH Procedure

Random access (RA) procedures may be used to establish communicationsbetween a wireless device and a base station in a cell. A four-step RAprocedure in FIG. 12 may have an associated latency, e.g., which may bea minimum of fourteen transmission time intervals (TTI). Reducing thenumber of steps in an RA procedure may reduce latency. By using paralleltransmissions, a four-step RA procedure may be reduced to a two-step RAprocedure. A two-step RA procedure may have an associated latency, e.g.,which may be a minimum of four TTIs and which may be less than anassociated latency for a four-step RA procedure.

FIG. 16 is an example of a two-step RA procedure that may comprise anuplink (UL) transmission of a two-step Msg1 that may comprise a randomaccess preamble (RAP) transmission and one or more transport blockstransmission, followed by a downlink (DL) transmission of a two-stepMsg2 that may comprise a response, e.g., random access response (RAR),corresponding to the uplink transmission. The response may comprisecontention resolution information. For example, the two-step Msg1 may bealso referred to as a message A (MsgA). For example, the two-step Msg2may be also referred to as a message B (MsgB).

A base station may transmit one or more RRC messages to configure awireless device with one or more parameters of two step RACHconfiguration. The one or more RRC messages may broadcast or multicastto one or more wireless devices. The one or more RRC messages may bewireless device-specific messages, e.g., a dedicated RRC messagetransmitted to a wireless device with RRC INACTIVE 1520 or RRC CONNECTED1530. The one or more RRC messages may comprise parameters required fortransmitting a two-step Msg1 in FIG. 16. For example, the parameter mayindicate at least one of following: PRACH resource allocation, preambleformat, SSB information (e.g., total number of SSBs, downlink resourceallocation of SSB transmission, transmission power of SSB transmission,and/or other information), and uplink radio resources for one or moretransport block transmissions.

In the UL transmission of a two-step RA procedure, a wireless device maytransmit, via a cell and to a base station, a RAP for UL time alignmentand/or one or more transport blocks (e.g., delay-sensitive data,wireless device ID, security information, device information such asIMSI, and/or other information). In the DL transmission of the two-stepRA procedure, a base station may transmit a two-step Msg2 (e.g., an RAR)that may comprise at least one of following: a timing advance commandindicating the TA value, a power control command, an UL grant (or RAR ULgrant), a wireless device ID for contention resolution, an RNTI (e.g.,C-RNTI or TC-RNTI), and/or other information. The two-step Msg2 (e.g.,an RAR) may comprise a preamble identifier corresponding to thepreamble, a positive or negative acknowledgement of a reception of theone or more transport blocks, and/or an indication of a successfuldecoding of the one or more transport blocks. A two-step RA proceduremay reduce RA latency compared with a four-step RA procedure, e.g., byintegrating a random access preamble transmission (e.g., a process toobtain a timing advance value) with one or more transport blocktransmissions.

In the UL transmission of a two-step RA procedure, a wireless device maytransmit, via a cell and to a base station, a RAP in parallel with oneor more TBs. The wireless device may acquire one or more configurationparameters for the UL transmission before the wireless device starts atwo-step RA procedure. For example, the one or more configurationparameters may indicate at least one of following: PRACH resourceallocation, preamble format, SSB information (e.g., a number oftransmitting SSBs, downlink resource allocation of SSB transmissions,transmission power of SSB transmission, and/or other information),uplink radio resources (in terms of time, frequency,code/sequence/signature) for one or more transport block transmissions,and power control parameters of one or more TB transmissions (e.g., celland/or UE specific power adjustments used for calculating receivedtarget power, inter-cell interference control parameter that may be usedas a scaling factor of pathloss measurement, reference signal power tocalculate for pathloss measurement, and/or one or more margins).

In a two-step RA procedure, a wireless device may transmit the RAP via aRACH resource indicated by a two-step RACH configuration. The wirelessdevice may transmit one or more TBs via an UL radio resource indicatedby a two-step RACH configuration. The transmission of the RAP may beoverlapped in time (partially or entirely) with the transmission of theone or more TBs. The two-step RACH configuration may indicate a portionof overlapping of radio resources between the RAP and one or more TBtransmissions. The two-step RACH configuration may indicate one or moreUL radio resources associated with one or more RAPs (or RAP groups)and/or the RACH resource. For example, based on a selection of an RAP,an RAP group, and/or an RACH resource, a wireless device may determineat least one UL radio resource where the wireless device transmits oneor more TBs as a part of a two-step RACH procedure. The one or more ULradio resources may be indicated based on a frame structure in FIG. 6,and/or OFDM radio structure in FIG. 8, e.g., with respect to an SFN(SNR=0), slot number, and/or OFDM symbol number for a time domain radioresource, and/or with respect to a subcarrier number, a number ofresource elements, a number of resource blocks, RBG number, and/orfrequency index for a frequency domain radio resource. For example, theone or more UL radio resources may be indicated based on a time offsetand/or a frequency offset with respect to one or more RACH resources ofa selected RAP. The UL transmissions may occur, e.g., in the samesubframe (or slot/mini-slot), in consecutive subframes (orslot/mini-slot), or in the same burst.

For example, a PRACH resource and one or more associated UL radioresources for a two-step Msg1 may be allocated with a time offset and/orfrequency offset, e.g., provided by RRC messages (as a part of RACHconfig.) and/or predefined (e.g., as a mapping table). FIG. 17A, FIG.17B, and FIG. 17C are examples of radio resource allocations of a PRACHresource and one or more associated UL radio resources based on a timeoffset, a frequency offset, and a combination of a time offset and afrequency offset, respectively. The examples in FIG. 17A, FIG. 17B, andFIG. 17C may be a case of a PRACH resource and a UL radio resource wherea single SSB transmission is configured. The examples may be a case of aPRACH resource and a UL radio resource associated with a first SSBtransmission of one or more SSB transmissions.

In an example, a base station may employ the RAP to adjust ULtransmission time for a cell and/or to aid in channel estimation for oneor more TBs. A portion of the UL transmission for one or more TBs in atwo-step RACH procedure may comprise, e.g., a wireless device ID, aC-RNTI, a service request such as buffer state reporting (e.g., a bufferstatus report) (BSR), one or more user data packets, and/or otherinformation. A wireless device in an RRC CONNECTED state may use aC-RNTI as an identifier of the wireless device (e.g., a wireless deviceID). A wireless device in an RRC INACTIVE state may use a C-RNTI (ifavailable), a resume ID, or a short MAC-ID as an identifier of thewireless device. A wireless device in an RRC IDLE state may use a C-RNTI(if available), a resume ID, a short MACID, an IMSI (InternationalMobile Subscriber Identifier), a T-IMSI (Temporary-IMSI), and/or arandom number as an identifier of the wireless device.

In a two-step RACH procedure, the UL transmission may comprise one ormore TBs that may be transmitted in one or more ways. One or moretransport blocks may be multiplexed with an RAP transmission in timeand/or frequency domains. A base station may configure one or moreresources reserved for the UL transmission that may be indicated to awireless device before the UL transmission. If a wireless devicetransmits one or more TBs in a two-step Msg1 of a two-step RA procedure,a base station may transmit in a two-step Msg2 (e.g., an RAR) that maycomprise a contention resolution message and/or an acknowledgement (ACKor NACK) message of the one or more TBs. A wireless device may transmitone or more second TBs after the reception of an RAR. The wirelessdevice may transmit an indicator, such as buffer state reporting, in atwo-step Msg1 of a two-step RA procedure. The indicator may indicate toa base station an amount of data the wireless device to transmit and/oran amount of data remains in a buffer. The base station may determine aUL grant based on the indicator. The base station may transmit the ULgrant to the wireless device via an RAR.

In a two-step/RA procedure, a wireless device may receive two separateresponses; a first response for RAP transmission; and a second responsefor one or more TB transmission. A wireless device may monitor a commonsearch space to detect the first response with a random access RNTIgenerated based on time and frequency indices of PRACH resource wherethe wireless device transmits an RAP. A wireless device may monitor acommon search space and/or a wireless device specific search space todetect the second response. To detect the second response, the wirelessdevice may employ a C-RNTI (e.g., if configured) or a random access RNTIgenerated based on time and frequency indices of PRACH resource wherethe wireless device transmits an RAP. The wireless device specificsearch space may be predefined and/or configured by an RRC message.

A two-step RA procedure may be initiated based on one or more case-basedprocedures, services, or radio conditions. For example, if a cell issmall such that there may be no need for a TA, a base station in thecell may configure one or more wireless devices under its coverage touse a two-step RA procedure. A wireless device may acquire theconfiguration, via one or more RRC messages (e.g., system informationblocks, multicast and/or unicast RRC signaling), and/or via L1 controlsignaling (e.g., PDCCH order) used to initiate a two-step RA procedure.

For example, in a macro coverage area, a wireless device may have astored and/or persisted TA value, e.g., a stationary or near stationarywireless device such as a sensor-type wireless device. In this case atwo-step RA procedure may be initiated. A base station having macrocoverage may use broadcasting and/or dedicated signaling to configure atwo-step RA procedure with one or more wireless devices having storedand/or persisted TA values under the coverage.

A wireless device in an RRC connected state may perform a two-step RAprocedure. For example, the two-step RA procedure may be initiated whena wireless device performs a handover (e.g., network-initiatedhandover), and/or when the wireless device requires or requests a ULgrant for a transmission of delay-sensitive data and there are nophysical-layer uplink control channel resources available to transmit ascheduling request. A wireless device in an RRC INACTIVE state mayperform a two-step RA procedure, e.g., for a small data transmissionwhile remaining in the RRC INACTIVE state or for resuming a connection.A wireless device may initiate a two-step RA procedure, for example, forinitial access such as establishing a radio link, re-establishment of aradio link, handover, establishment of UL synchronization, and/or ascheduling request when there is no UL grant.

The following description presents one or more examples of a RACHprocedure. The procedures and/or parameters described in the followingmay not be limited to a specific RA procedure. The procedures and/orparameters described in the following may be applied for a four-step RAprocedure and/or a two-step RA procedure. For example, a RA proceduremay refer to a four-step RA procedure and/or a two-step RA procedure inthe following description.

Example of RACH Procedure

In an example, a base station may transmit, to a wireless device, one ormore messages indicating random access parameters of a four-step randomaccess procedure in FIG. 12 and/or a two-step random access procedure inFIG. 16. For example, the one or more messages may be broadcast RRCmessage, wireless device specific RRC message, and/or combinationthereof. For example, the one or more message may comprise at least oneof RACH-ConfigCommon, RACH-ConfigGeneric, and RACH-ConfigDedicated. Forexample, for a contention based (four-step and/or a two-step) randomaccess procedure, a wireless device may receive, from a base station, atleast RACH-ConfigCommon and RACH-ConfigGeneric. For example, for acontention free (four-step and/or a two-step) random access procedure, awireless device may receive, from a base station, at leastRACH-ConfigDedicated.

For example, a random access procedure may be initiated in one or moreways based at least on one of RACH-ConfigCommon, RACH-ConfigGeneric, andRACH-ConfigDedicated. For example, a random access procedure may beinitiated by a PDCCH order transmitted by a base station, by the MACentity of a wireless device, or by RRC. There may be one random accessprocedure ongoing at any point in time in a MAC entity. A random accessprocedure on an SCell may be initiated by a PDCCH order withra-PreambleIndex different from a first index (that may be predefined orconfigured e.g., 0b000000). For example, if the MAC entity of a wirelessdevice receives a request for a random access procedure while another isalready ongoing in the MAC entity, a wireless device may continue withthe ongoing procedure or start with the new procedure (e.g. for SIrequest).

In an example, a base station may transmit one or more RRC message toconfigure a wireless device at least one of following parameters for arandom access procedure:

prach-ConfigIndex: the available set of PRACH occasions for thetransmission of the Random Access Preamble;

preambleReceivedTargetPower: initial Random Access Preamble power;

rsrp-ThresholdSSB: an RSRP threshold for the selection of the SSB andcorresponding Random Access Preamble and/or PRACH occasion. If theRandom Access procedure is initiated for beam failure recovery,rsrp-ThresholdSSB refers to rsrp-ThresholdSSBinBeamFailureRecoveryConfig IE;

rsrp-ThresholdCSI-RS: an RSRP threshold for the selection of CSI-RS andcorresponding Random Access Preamble and/or PRACH occasion. If theRandom Access procedure is initiated for beam failure recovery,rsrp-ThresholdCSI-RS shall be set to a value calculated by multiplyingrsrp-ThresholdSSB in BeamFailureRecoveryConfig IE by powerControlOffset;

rsrp-ThresholdSSB-SUL: an RSRP threshold for the selection between theNUL carrier and the SUL carrier;

powerControlOffset: a power offset between rsrp-ThresholdSSB andrsrp-ThresholdCSI-RS to be employed when the Random Access procedure isinitiated for beam failure recovery;

powerRampingStep: the power-ramping factor;powerRampingStepHighPriority: the power-ramping factor in case ofdifferentiated Random Access procedure

ra-PreambleIndex: an index of Random Access Preamble;

ra-ssb-OccasionMaskIndex: defines PRACH occasion(s) associated with anSSB in which the MAC entity may transmit a Random Access Preamble;

ra-OccasionList: defines PRACH occasion(s) associated with a CSI-RS inwhich the MAC entity may transmit a Random Access Preamble;

preambleTransMax: the maximum number of Random Access Preambletransmission

ssb-perRACH-OccasionAndCB-PreamblesPerSSB: defines the number of SSBsmapped to each PRACH occasion and the number of Random Access Preamblesmapped to each SSB;

the set of Random Access Preambles and/or PRACH occasions for SIrequest, if any;

the set of Random Access Preambles and/or PRACH occasions for beamfailure recovery request, if any;

ra-ResponseWindow: the time window to monitor RA response(s);

ra-ContentionResolutionTimer: the Contention Resolution Timer.

In an example, a random access procedure may be initiated for beamfailure detection and recovery. For example, a wireless device may beconfigured by RRC with a beam failure recovery procedure which may beemployed for indicating to the serving base station of a SSB or CSI-RSwhen beam failure is detected on the serving SSB(s)/CSI-RS(s). Beamfailure may be detected by counting one or more beam failure instanceindication from the lower layers to the MAC entity. For example, a basestation may configure, via RRC, the following parameters in theBeamFailureRecoveryConfig for the Beam Failure Detection and Recoveryprocedure: beamFailureInstanceMaxCount for the beam failure detection;

beamFailureDetectionTimer for the beam failure detection;

beamFailureRecoveryTimer for the beam failure recovery procedure;

rsrp-ThresholdSSB: an RSRP threshold for the beam failure recovery;

powerRampingStep: powerRampingStep for the beam failure recovery;

preambleReceivedTargetPower: preambleReceivedTargetPower for the beamfailure recovery; preambleTransMax: preambleTransMax for the beamfailure recovery;

ra-ResponseWindow: the time window to monitor response(s) for the beamfailure recovery using contention-free Random Access Preamble;

prach-ConfigIndex: prach-ConfigIndex for the beam failure recovery;

ra-ssb-OccasionMaskIndex: ra-ssb-OccasionMaskIndex for the beam failurerecovery;

ra-OccasionList: ra-OccasionList for the beam failure recovery.

In an example, a wireless device may employ one or more parameters for arandom access procedure. For example, a wireless device may employ atleast one of PREAMBLE_INDEX; PREAMBLE_TRANSMISSION_COUNTER;PREAMBLE_POWER_RAMPING_COUNTER; PREAMBLE_POWER_RAMPING_STEP;PREAMBLE_RECEIVED_TARGET_POWER; PREAMBLE_BACKOFF; PCMAX;SCALING_FACTOR_BI; and TEMPORARY_C-RNTI.

In an example, a wireless device may perform random access resourceselection for selecting one or more preambles and one or more PRACHoccasion (or resources comprising time, frequency, and/or code). Forexample, there may be one or more cases that a random access proceduremay be initiated for beam failure recovery; and/or thebeamFailureRecoveryTimer is either running or not configured; and/or thecontention-free Random Access Resources for beam failure recoveryrequest associated with any of the SSBs and/or CSI-RSs have beenexplicitly provided by RRC; and/or at least one of the SSBs with SS-RSRPabove rsrp-ThresholdSSB amongst the SSBs in candidateBeamRSList or theCSI-RSs with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the CSI-RSs incandidateBeamRSList is available. In this case, a wireless device mayselect an SSB with SS-RSRP above rsrp-ThresholdSSB amongst the SSBs incandidateBeamRSList or a CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RSamongst the CSI-RSs in candidateBeamRSList. For example, if CSI-RS isselected, and there is no ra-PreambleIndex associated with the selectedCSI-RS, a wireless device may set the PREAMBLE_INDEX to ara-PreambleIndex corresponding to the SSB in candidateBeamRSList whichis quasi-collocated with the selected CSI-RS, otherwise the wirelessdevice may set the PREAMBLE_INDEX to a ra-PreambleIndex corresponding tothe selected SSB or CSI-RS from the set of Random Access Preambles forbeam failure recovery request.

For example, there may be one or more cases that a random accessprocedure may be initiated and/or a ra-PreambleIndex has been explicitlyprovided by either PDCCH or RRC; and/or the ra-PreambleIndex is not afirst preamble index (that may be predefined or configured e.g.,0b000000); and/or contention-free Random Access Resource associated withSSBs or CSI-RSs have not been explicitly provided by RRC. In this case,a wireless device may set the PREAMBLE_INDEX to the signalledra-PreambleIndex.

For example, there may be one or more cases that a random accessprocedure may be initiated and/or the contention-free Random AccessResources associated with SSBs have been explicitly provided by RRC andat least one SSB with SS-RSRP above rsrp-ThresholdSSB amongst theassociated SSBs is available. In this case, a wireless device may selectan SSB with SS-RSRP above rsrp-ThresholdSSB amongst the associated SSBs.For example, the wireless device may set the PREAMBLE_INDEX to ara-PreambleIndex corresponding to the selected SSB.

For example, there may be one or more cases that a random accessprocedure may be initiated and the contention-free random accessresources associated with CSI-RSs have been explicitly provided by RRCand at least one CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongstthe associated CSI-RSs is available. In this case, a wireless device mayselect a CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongst theassociated CSI-RSs. for example, the wireless device may set thePREAMBLE_INDEX to a ra-PreambleIndex corresponding to the selectedCSI-RS.

For example, there may be one or more cases that a random accessprocedure may be initiated and at least one of the SSBs with SS-RSRPabove rsrp-ThresholdSSB is available. In this case, for example, awireless device may select an SSB with SS-RSRP above rsrp-ThresholdSSB,otherwise may select any SSB. For example, a random access resourceselection is performed when Msg3 1240, two-step Msg1, and/or one or moreTBs in FIG. 16 is being retransmitted, a wireless device may select thesame group of Random Access Preambles as was employed for the RandomAccess Preamble transmission attempt corresponding to the firsttransmission of Msg3, two-step Msg1, and/or one or more TBs. Forexample, if the association between random access preambles and SSBs isconfigured, a wireless device may select a ra-PreambleIndex randomlywith equal probability from the Random Access Preambles associated withthe selected SSB and the selected Random Access Preambles group. Forexample, if the association between random access preambles and SSBs isnot configured, a wireless device may select a ra-PreambleIndex randomlywith equal probability from the Random Access Preambles within theselected Random Access Preambles group. For example, a wireless devicemay set the PREAMBLE INDEX to the selected ra-PreambleIndex.

In an example, if an SSB is selected above and an association betweenPRACH occasions and SSBs is configured, a wireless device may determinethe next available PRACH occasion from the PRACH occasions correspondingto the selected SSB permitted by the restrictions given by thera-ssb-OccasionMaskIndex if configured (the MAC entity of the wirelessdevice may select a PRACH occasion randomly with equal probabilityamongst the PRACH occasions occurring simultaneously but on differentsubcarriers, corresponding to the selected SSB; the MAC entity may takeinto account the possible occurrence of measurement gaps whendetermining the next available PRACH occasion corresponding to theselected SSB).

In an example, if a CSI-RS is selected above and an association betweenPRACH occasions and CSI-RSs is configured. a wireless device maydetermine the next available PRACH occasion from the PRACH occasions inra-OccasionList corresponding to the selected CSI-RS (the MAC entityshall select a PRACH occasion randomly with equal probability amongstthe PRACH occasions occurring simultaneously but on differentsubcarriers, corresponding to the selected CSI-RS; the MAC entity maytake into account the possible occurrence of measurement gaps whendetermining the next available PRACH occasion corresponding to theselected CSI-RS).

In an example, if a CSI-RS is selected above and there is nocontention-free Random Access Resource associated with the selectedCSI-RS, a wireless device may determine the next available PRACHoccasion from the PRACH occasions, permitted by the restrictions givenby the ra-ssb-OccasionMaskIndex if configured, corresponding to the SSBin candidateBeamRSList which is quasi-collocated with the selectedCSI-RS (the MAC entity may take into account the possible occurrence ofmeasurement gaps when determining the next available PRACH occasioncorresponding to the SSB which is quasi-collacted with the selectedCSI-RS).

For example, a wireless device may determine the next available PRACHoccasion (the MAC entity shall select a PRACH occasion randomly withequal probability amongst the PRACH occasions occurring simultaneouslybut on different subcarriers; the MAC entity may take into account thepossible occurrence of measurement gaps when determining the nextavailable PRACH occasion).

For example, based on a selected PREABLE INDEX and PRACH occasion, awireless device may perform the random access preamble transmission. Forexample, if the notification of suspending power ramping counter has notbeen received from lower layers; and/or if SSB selected is not changed(i.e. same as the previous Random Access Preamble transmission), awireless device may increment PREAMBLE_POWER_RAMPING_COUNTER by 1. thewireless device may select a value of DELTA_PREAMBLE that may bepredefined and/or semi-statically configured by a base station and setPREAMBLE_RECEIVED_TARGET_POWER topreambleReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_POWER_RAMPING_COUNTER−1)×PREAMBLE_POWER_RAMPING_STEP.

The wireless device may instruct the physical layer to transmit theRandom Access Preamble using the selected PRACH, corresponding RA-RNTI(if available), PREAMBLE_INDEX and PREAMBLE_RECEIVED_TARGET_POWER. Forexample, the wireless device may compute an RA-RNTI associated with thePRACH occasion in which the Random Access Preamble is transmitted, e.g.,In an example, the RA-RNTI associated with the PRACH in which the RandomAccess Preamble is transmitted, may be computed in terms of index of thefirst OFDM symbol of the specified PRACH, an index of the first slot ofthe specified PRACH in a system frame, an index of the specified PRACHin the frequency domain, and/or uplink carrier indicator. For example,an example RA-RNTI may be calculated as:RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id where s_id isthe index of the first OFDM symbol of the specified PRACH (0≤s_id<14),t_id is the index of the first slot of the specified PRACH in a systemframe (0≤t_id<80), f_id is the index of the specified PRACH in thefrequency domain (0≤f_id<8), and ul_carrier_id is the UL carrier usedfor Msg1 1220 transmission or two-step Msg1 1620 (0 for NUL carrier, and1 for SUL carrier or vice versa).

For example, a wireless device, that transmitted a random accesspreamble, may start to monitor a downlink control channel for a randomaccess response corresponding to the random access preamble. Thepossible occurrence of a measurement gap may not determine when awireless device starts to monitor a downlink control channel.

If a wireless device does not perform a contention-free random accessprocedure for beam a failure recovery request, the wireless device maystart a random access window (e.g., ra-ResponseWindow) configured in arandom access configuration parameter (e.g., RACH-ConfigCommon) at afirst downlink control channel occasion from an end of a random accesspreamble transmission. The wireless device may monitor the firstdownlink control channel occasion of the SpCell for random accessresponse(s) identified by the RA-RNTI while a random access responsewindow (e.g., ra-ResponseWindow) is running.

In an example, a downlink assignment may be received by a wirelessdevice, on the PDCCH for the RA-RNTI and the received TB (e.g., MAC PDUcomprising one or more random access responses is successfully decoded.For example, the MAC PDU may comprise a MAC subPDU with Random AccessPreamble identifier corresponding to a preamble that a wireless devicetransmits to a base station. In this case, the wireless device maydetermine that this random access response reception may be successful.For example, the MAC subPDU may comprise a preamble index (e.g., RAPID)only, e.g., for a random access procedure initiated for a systeminformation request

In an example embodiment, Listen-before-talk (LBT) may be implementedfor transmission in a cell configured in unlicensed band (referred to asa LAA cell and/or a NR-U cell for the sake of convenience, for example,an LAA cell and NR-U cell may be interchangeable and may refer any celloperating in unlicensed band. The cell may be operated as non-standalonewith an anchor cell in licensed band or standalone without an anchorcell in licensed band). The LBT may comprise a clear channel assessment.For example, in an LBT procedure, equipment may apply a clear channelassessment (CCA) check before using the channel. For example, the CCAutilizes at least energy detection to determine the presence or absenceof other signals on a channel in order to determine if a channel isoccupied or clear, respectively.

In an example, contention-based random access (CBRA) and/orcontention-free random access (CFRA) may be supported on SpCell. CFRAmay be supported on SCells. In an example, an RAR may be transmitted viaSpCell, e.g., non-standalone scenario. In an example, an RAR may betransmitted via SpCell and/or SCell, e.g., standalone scenario. In anexample, a predefined HARQ process ID for an RAR.

In a RA procedure, a wireless device may receive from a base station atleast one RAR as a response of Msg1 1220 or two-step Msg1. An RAR may bein a form of MAC PDU comprising one or more MAC subPDUs and optionallypadding. FIG. 18A is an example of an RAR. A MAC subheader may be octetaligned. Each MAC subPDU may comprise at least one of following: a MACsubheader with Backoff Indicator only; a MAC subheader with RAPID only(i.e. acknowledgment for SI request); a MAC subheader with RAPID and MACRAR. FIG. 18B is an example of a MAC subheader with backoff indicator.For example, a MAC subheader with backoff indicator comprise one or moreheader fields, e.g., E/T/R/R/BI as described in FIG. 18B. A MAC subPDUwith backoff indicator may be placed at the beginning of the MAC PDU, ifincluded. MAC subPDU(s) with RAPID only and MAC subPDU(s) with RAPID andMAC RAR may be placed anywhere after MAC subPDU with Backoff Indicatorand, if exist before padding as described in FIG. 18A. A MAC subheaderwith RAPID may comprise one or more header fields, e.g., E/T/RAPID asdescribed in FIG. 18C. Padding may be placed at the end of the MAC PDUif present. Presence and length of padding may be implicit based on TBsize, size of MAC subPDU(s).

In an example one or more header fields in a MAC subheader may indicateas follow: an E field may indicate an extension field that may be a flagindicating if the MAC subPDU including this MAC subheader is the lastMAC subPDU or not in the MAC PDU. The E field may be set to “1” toindicate at least another MAC subPDU follows. The E field may be set to“0” to indicate that the MAC subPDU including this MAC subheader is thelast MAC subPDU in the MAC PDU; a T filed may be a flag indicatingwhether the MAC subheader contains a Random Access Preamble ID or aBackoff Indicator (one or more backoff values may predefined and BI mayindicate one of backoff value). The T field may be set to “0” toindicate the presence of a Backoff Indicator field in the subheader(BI). The T field may be set to “1” to indicate the presence of a RandomAccess Preamble ID field in the subheader (RAPID); an R filed mayindicate a reserved bit that may be set to “0”; a BI field may be abackoff indicator field that identifies the overload condition in thecell. The size of the BI field may be 4 bits; an RAPID field may beaRandom Access Preamble IDentifier field that may identify thetransmitted Random Access Preamble. If the RAPID in the MAC subheader ofa MAC subPDU corresponds to one of the Random Access Preamblesconfigured for SI request, MAC RAR may not be included in the MACsubPDU.

There may be one or more MAC RAR format. At least one of following MACRAR format may be employed in a four-step or a two-step RA procedure.The MAC RAR may be fixed size and may comprise at least one of thefollowing fields: an R field that may indicate a Reserved bit, set to“0”; a Timing Advance Command field that may indicate the index value TAemployed to control the amount of timing adjustment; a UL Grantfieldthat indicate the resources to be employed on the uplink; and a RNTIfield (e.g., Temporary C-RNTI and/or C-RNTI) that may indicate anidentity that is employed during Random Access. For example, for atwo-step RA procedure, an RAR may comprise at least one of following: aUE contention resolution identity, an RV ID for retransmission of one ormore TBs, decoding success or failure indicator of one or more TBtransmission, and one or more fields.

There may be a case that a base station may multiplex, in a MAC PDU,RARs for two-step and four-step RA procedures. If RARs for two-step andfour-step RA procedure have the same size, a wireless device may notrequire an RAR length indicator field and/or the wireless device maydetermine the boundary of each RAR in the MAC PDU based onpre-determined RAR size information. The RAR may be a fixed size usingthe same format for two-step and four-step RA procedures.

In an example, an RAR for a two-step RA procedure may have a differentformat, size, and/or fields, from an RAR for a four-step RA procedure.If RARs for two-step and four-step RA procedures are multiplexed into aMAC PDU, and the RARs have different format between two-step andfour-step RA procedure, an RAR may have a field to indicate a type ofRAR (e.g., a reserved “R” field may be employed to indicate a type ofRAR). A field for indicating an RAR type may be in a subheader (such asa MAC subheader) or in an RAR. An RAR may comprise different types offields that may correspond with an indicator in a subheader or in anRAR. A wireless device may determine the boundary of one or more RARs ina MAC PDU based on one or more indicators.

In an example, for an SCell addition, a base station may be aware ofwhether SUL carrier(s) is (are) configured in an SCell, and/or whichcarrier is allowed to be employed for an SCell addition. A base stationmay configure DL measurements on NUL carrier(s) and/or SUL carrier(s). Abase station may configure a wireless device with one or more RACHconfigurations for an SCell, e.g., a first RACH configuration for an SULcarrier, a second RACH configuration for a NUL carrier, and so on. Abase station may transmit, to a wireless device via a PDCCH ordercomprising a parameter indicating in which carrier the wireless devicestarts a (contention free or contention based) random access procedure.For example, a PDCCH order triggering a (contention free or contentionbased) random access procedure may comprise one or more parametersindicating at least one of at least one preamble (e.g., preamble index),one or more PRACH resources (e.g., PRACH mask index), an SUL indicator,and/or a BWP indicator. For example, for an random access procedure, awireless device receiving a PDCCH order may transmit at least onepreamble via one or more PRACH resources of a BWP indicated by a BWPindicator of a carrier indicated by an SUL indicator.

In an example, a wireless device may determine a random access procedureunsuccessfully completed. For example, if a wireless device receives noRAR corresponding to one or more preambles transmitted by the wirelessdevice during a random access procedure, the wireless device mayconsider the random access procedure unsuccessfully completed. There maybe a number of preamble transmissions allowed during a random accessprocedure (e.g., preambleTransMax), wherein the number of preambletransmissions may be semi-statically configured by RRC. For example, ifa wireless device receives no RAR corresponding to the number ofpreamble transmissions, the wireless device may consider a random accessprocedure unsuccessfully completed. In response to an unsuccessfulcompletion of a random access procedure, a wireless device may indicatea problem to upper layer(s), wherein, in response to the indicatedproblem, the upper layers(s) may trigger radio link failure that maylead to prolonged random access delay and degraded user experience.

For example, a base station (source base station and/or a target gNB)configuring a wireless device with a RACH configuration for a randomaccess (for a handover and/or SCell addition) may not allow to reuse theRACH configuration if the random access is unsuccessfully completed.

In an unlicensed band, a failure of a random access may occur due toLBT. For example, in an unlicensed band, at least one LBT may beperformed prior to DL and/or UL transmission. For example, in a randomaccess procedure in FIG. 12, Msg 1 1220, Msg 2 1230, Msg 3 1240, andcontention resolution 1250 may require at least one LBT before thetransmission for contention based random access, e.g., at least 4 LBTs.For contention-free case, Msg 1 1220 and Msg2 1230 may require at leastone LBT, e.g., at least 2 LBTs. FIG. 19 is an example diagram ofcontention based and contention-free random access procedures with LBT.

In an example, a base station and/or a wireless device may not transmita message (e.g., Msg 1, Msg 2, Msg 3, and contention resolution) for arandom access procedure if LBT is failed prior to transmitting themessage, e.g., CCA in LBT determines that a channel in unlicensed bandis busy (occupied by other device). In an example, a failure of LBT mayresult in degrading a user experience (e.g., in terms of QoS, capacity(throughput), and/or coverage). For example, a base station and/or awireless device may wait until the channel becomes idle. This may resultin a latency problem to make a radio link connection between a basestation and a wireless device. For example, a failure of an LBT during arandom access procedure may lead a long delay for a wireless device toreceive an UL grant and/or TA value from a base station. This may resultin a call drop and/or traffic congestion. For example, a failure of anLBT in a random access procedure for an SCell addition may lead a cellcongestion (e.g., load imbalancing) on one or more existing cells, e.g.,since an SCell may not take over traffic from the one or more existingcells in time.

In an example, there may be a need to improve an efficiency of randomaccess procedure operating in unlicensed band, e.g., to compensate alatency/delay, and/or performance degradation, due to the LBT failure.For example, selecting two or more SSBs and performing one or more LBTson one or more PRACH occasions associated with the two or more SSBs myincrease a success rate of LBT. For example, a wireless device maymeasure a plurality of downlink reference signals (SSBs or CSI-RSs, ifCSI-RS is configured by RRC). The wireless device may select two or moreSSBs by comparing RSRPs of the plurality of downlink reference signalsand a threshold. For example, the threshold may comprisersrp-ThresholdSSB when the plurality of downlink reference signals areSSBs. For example, the threshold may comprise rsrp-ThresholdCSI-RS whenthe plurality of downlink reference signals are CSI-RSs. For example,the wireless device may select two or more downlink referencing signals(SSBs or CSI-RSs) whose RSRPs are higher than the threshold. Forexample, if SSBs are configured with the wireless device, the wirelessdevice may determine one or more PRACH occasions associated with theselected two or more downlink reference signals, e.g., SSBs. Forexample, the wireless device may determine the one or more PRACH basedon an association between PRACH occasions and SSBs that may be indicatedby one or more RRC parameters, e.g., ra-ssb-OccasionMaskIndex. Forexample, if CSI-RSs are configured with the wireless device, thewireless device may determine one or more PRACH occasions associatedwith the selected two or more downlink reference signals, e.g., CSI-RSs.For example, the wireless device may determine the one or more PRACHbased on an association between PRACH occasions and CSI-RSs that may beindicated by one or more RRC parameters, e.g., ra-OccasionList.

In an example, a two-step RA procedure may employ LBT in an unlicensedband. FIG. 20 is an example diagram of a two-step RA procedure with LBT.A base station and/or a wireless device may not transmit a message(e.g., two-step Msg 1, preamble, one or more transport blocks, and/ortwo-step Msg 2) for a random access procedure if LBT is failed prior totransmitting the message, e.g., CCA in LBT determines that a channel inunlicensed band is busy (occupied by other device). The transmissions ofPreamble and for one or more transport blocks may have a same LBT and/ordifferent LBTs.

For example, radio resources for transmissions of Preamble and one ormore transport blocks may be configured in a same channel (or a samesubband or a same BWP or a same UL carrier), where a wireless deviceperforms an LBT for the transmissions (e.g., based on a regulation). Inthis case, an LBT result on the same channel (or the same subband or thesame BWP or the same UL carrier) may applied for transmissions ofPreamble and for one or more transport blocks. For example, FIG. 21 isan example of radio resource allocation for a two-step RA procedure. Ifa frequency offset in FIG. 21 is zero, PRACH and UL radio resources maybe time-multiplexed. If a time-offset in FIG. 21 is zero, PRACH and ULradio resources may be frequency-multiplexed. The frequency offset inFIG. 21 may be an absolute number in terms of Hz, MHz, and GHz, and/or arelative number, e.g., one of frequency indicespredefined/preconfigured. The time-offset in FIG. 21 may be an absolutenumber in terms of micro-second, milli-second, or second and/or arelative number, e.g., in terms of subframe, slot, mini-slot, OFDMsymbol. PRACH for transmission of preamble and UL radio resources fortransmission of one or more TBs may be subject to one LBT if f1 and f2are configured in the same channel (or a same subband or a same BWP or asame UL carrier). For example, in FIG. 21, one LBT before PRACH may beperformed by a wireless device (e.g., based on a regulation ofunlicensed band). For example, a number of LBTs may be determined basedon a value of time-offset in FIG. 21. For example, one LBT before PRACHmay be performed by a wireless device if the value of time-offset isequal to and/or less than a threshold (that may be configured and/ordefined by a regulation). For example, the one LBT determines idle, awireless device may perform a transmission of Preamble via PRACHfollowed by a second transmission of one or more TBs via the UL radioresources with no LBT (the transmission order may be switched if the ULradio resources is allocated before PRACH in time domain). This may be acase that PRACH and UL radio resources are allocated closely enough intime domain. For example, if the value of time-offset is larger than thethreshold, a wireless device may perform a first LBT before PRACH andperform a second LBT before UL radio resources.

For example, a bandwidth of BWP and/or UL carrier is larger than a firstvalue (e.g., 20 MHz) and f1 and f2 are configured in the bandwidth, awireless may perform an LBT and apply a result (idle/busy) of the LBT tothe transmission of preamble and UL radio resources for transmission ofone or more TBs. For example, if the channel is idle, a wireless devicemay perform the transmissions of Preamble and for one or more transportblocks. If the channel is busy, a wireless device may not perform thetransmissions of Preamble and for one or more transport blocks.

For example, a bandwidth of BWP and/or UL carrier is less than a firstvalue (e.g., 20 MHz) and f1 and f2 are configured in the bandwidth, awireless may perform an LBT and apply a result (idle/busy) of the LBT tothe transmission of preamble and UL radio resources for transmission ofone or more TBs. For example, if the channel is idle, a wireless devicemay perform a first transmissions of Preamble followed by a secondtransmission of one or more transport blocks. If the channel is busy, awireless device may not perform the transmissions of Preamble and forone or more transport blocks.

For example, radio resources for transmissions of Preamble and one ormore transport blocks may be configured in different channels (ordifferent subbands or different BWPs or different UL carriers e.g., onein NUL and the other one in SUL) that may require separate LBTs. Forexample, a wireless device may perform an LBT per one or more channels,per one or more subbands, per one or more BWPs, and/or per one or moreUL carriers. FIG. 22 is an example of one or more LBTs performed for atwo-step RA procedure. In some cases, UL radio resources may beallocated before or aligned with PRACH in time. A wireless device mayperform a first LBT (e.g., LBT in FIG. 22) before a first transmissionof preamble (e.g., via PRACH) and perform a second LBT (e.g., LBT inFIG. 22) before a second transmission of one or more transport blocks(e.g., via UL radio resources). Depending on results of the first LBTand the second LBT, a wireless device may perform none of, one of, orboth of the first transmission and the second transmission.

For example, the first transmission may be performed when a first resultof the first LBT is idle. The second transmission may be independent ofthe first result. For example, the second transmission may be performedwhen a second result of the second LBT is idle. In this case, there maybe a case that a wireless device may transmit Preamble in response tothe first LBT being idle and may not be able to transmit one or moretransport blocks in response to the second LBT being busy. For example,a wireless device may not transmit Preamble in response to the first LBTbeing busy and may transmit one or more transport blocks in response tothe second LBT being idle. In a two-step RA procedure, one or moretransport blocks may comprise an identifier of the wireless device sothat a base station may identify which wireless device transmit the oneor more transport blocks. The identity may be configured by the basestation and/or may be at least a portion of wireless device-specificinformation, e.g., resume ID, DMRS sequence/index, IMSI, etc. If awireless device transmits one or more TBs with no Preamble (e.g., when achannel, e.g. PRACH is busy), a base station may identify the wirelessdevice based on the identity in the one or more TBs.

In a two-step RA procedure configured in an unlicensed band, theseparate LBTs for transmissions of Preamble and one or more TBs may beperformed in one or more cases. For example, a base station mayconfigure a wireless device with the separate LBTs for a widebandoperation (e.g., for a case that a bandwidth may be larger than 20 MHz).In the wideband operation, a base station may configure a wirelessdevice with a wideband comprising one or more subbands and/or one ormore BWPs. Some of the one or more subbands may be overlapped to eachother at least a portion in frequency domain. Some of the one or moresubbands may not be overlapped to each other at least a portion infrequency domain. Some of the one or more BWPs may be overlapped to eachother at least a portion in frequency domain. Some of the one or moreBWPs may not be overlapped to each other at least a portion in frequencydomain. In a wideband operation, if two radio resources are allocatedwith a space larger than a threshold (e.g., 20 MHz) in frequency domain,separate LBTs may be required for transmissions via the two radioresources. For example, a wideband may comprise one or more subbands,and two radio resources may be allocated in different subbands. In thiscase, a first transmission scheduled in a first subband requires a firstLBT, and a second transmission scheduled in a second subband requires asecond LBT. The first LBT and the second LBT may be independent of eachother.

For example, UL radio resources for transmission of one or more TBs maybe subject to a first LBT (e.g., LBT) and be independent of a second LBT(e.g., LBT) for transmission of Preamble. For example, PRACH fortransmission of Preamble may be subject to a second LBT (e.g., LBT) andbe independent of a first LBT (e.g., LBT) for transmission of one ormore TBs. For example, if f1 and f2 are configured in different channels(or different subbands or different BWPs or different UL carriers), awireless device may perform separate LBTs for a first transmissions ofPreamble and a second transmission of one or more transport blocks.

For example, FIG. 23A and FIG. 23B are examples of one or more LBTsperformed for a two-step RA procedure in an unlicensed band. Theresource allocation and the separate LBTs in FIG. 22 may be resultedfrom FIG. 23A and/or FIG. 23B. For example, a base station may configurea wireless device with one or more PRACH and one or more UL radioresources in different channels (BWPs and/or UL carriers). The wirelessdevice may one or more first opportunities to transmit preambles and oneor more second opportunities to transmit one or more TBs. For example,in FIG. 23A, a wireless device may have two opportunities (e.g., PRACH)for preamble transmission. Depending on LBT results, a wireless devicemay select one of two opportunities. For example, a wireless device mayperform a first LBT and a second LBT (e.g., in FIG. 23A). If the resultsof the first and second LBTs are idle, a wireless device may select oneof PRACH associated either a first LBT or a second LBT (e.g., based onrandom selection). If one of LBT result is idle and the other of LBTresult is busy, a wireless device may select PRACH associated with theLBT being idle for preamble transmission. If the first and second LBTsare busy, a wireless device may not transmit a preamble and may performone or more LBTs for one or more TB transmissions.

A wireless device may have one or more opportunities for transmission ofone or more TBs via UL radio resources (e.g., in a similar way that awireless device has for preamble transmission above). For example, theone or more opportunities for transmission of one or more TBs may beindependent of one or more opportunities for transmission of preamble.For example, if a wireless device does not transmit a preamble due to aresult (busy) of LBT, the wireless device may perform one or more LBTsto gain access to a channel to transmit one or more TBs. For example, inFIG. 23A, a wireless device may have a first LBT followed by a firsttransmission opportunity of one or more TBs via first UL radio resourcesand a second LBT (e.g., in FIG. 23A) followed by a second transmissionopportunity of one or more TBs via second UL radio resources. Dependingon LBT results, a wireless device may select one of opportunities. Forexample, in FIG. 23A, if (a first) LBT is busy but (a second) LBT isidle, a wireless device may transmit one or more TBs via UL radioresources (associated with the second LBT). If one or more LBTs to gainaccess for transmitting a preamble are busy, a wireless device may nottransmit any preamble. In this case, a wireless device may perform oneor more second LBTs (e.g., in FIG. 23A) for transmission of one or moreTBs.

For example, before a wireless device initiates a two-step RA procedure,the wireless device may receive, from a base station, control message(s)(e.g., RRC and/or PDCCH) indicating one or more associations betweenPRACH and UL radio resources. The associations may be one-to-one,multi-to-one, one-to-multi, and/or multi-to-multi between one or morePRACHs and one or more UL radio resources. Based on the associations, awireless device may determine which UL radio resources and/or whichPRACH need to be selected. For example, in FIG. 23A, the associationsmay indicate one-to-multi association from PRACH on channel 2 to ULradio resources on channel 1 and UL radio resources on channel 2. Forexample, the associations may indicate one-to-one association from PRACHon channel 1 to UL radio resources on channel 1. In this case, awireless device may perform one or more LBTs (depending on a regulationand/or resource allocation whether they are in the same channel) fortransmission of one or more TBs depending on a selection of PRACH. Forexample, in FIG. 23A, a wireless device may perform two LBTs (forPRACHs). If LBT on channel 2 may be idle but LBT on channel 1 may bebusy, a wireless device transmits a preamble via PRACH on channel 2. Thewireless device may choose one or more candidate UL radio resourcesbased on a configured association of PRACH on channel 2, which may beone-to-multi from PRACH on channel 2 to UL radio resources on channel 1and UL radio resources on channel 2. The wireless device may perform LBTon channel 1 and LBT on channel 2 (for the UL resources) based on theconfigured association. Depending on the results of the LBTs, a wirelessdevice may transmit one or more TBs. FIG. 23B is an example of atwo-step RA procedure. In this case, UL radio resources is associatedwith one PRACH. For example, a base station configured an associationfrom PRACH on channel 2 to UL radio resources on channel 1 and UL radioresources on channel 2.

The PRACH and/or UL radio resources in FIG. 21, FIG. 22, FIG. 23A,and/or FIG. 23B may be associated with at least one reference signalconfiguration (SSB, CSI-RS, DM-RS). A base station may transmit at leastone control message to a wireless device to indicate such anassociation. If the base station transmit a plurality of referencesignals, a configuration of each reference signal have an associationwith at least one PRACH, that may be configured by RRC and/or PDCCH. Indownlink channel, there may be a plurality of PRACHs and a plurality ofUL radio resources associated with the plurality of PRACHs.

In an example, there may be a need to improve an efficiency of randomaccess procedure operating in unlicensed band, e.g., to compensate alatency/delay, and/or performance degradation, due to the LBT failure.

In an example, in response to a PRACH transmission, the wireless devicemay attempt to detect a DCI (e.g., DCI format 1_0) during a window(e.g., ra-responseWindow). In an example, the DCI may be with CRCscrambled by a corresponding RA-RNTI.

In an example, the base station may provide the wireless device with alength of the window by a higher layer parameter ra-ResponseWindow. Inan example, the length of the window may be in number of slots. In anexample, the wireless device may determine a slot duration for thelength of the window based on the SCS for the Type1-PDCCH CSS set.

In an example, the wireless device may detect the DCI (e.g., DCI format1_0) with CRC scrambled by the corresponding RA-RNTI within the window.In an example, the wireless device may detect a transport block in aPDSCH within the window. In an example, the DCI may schedule thetransport block in the PDSCH. In an example, in response to thedetecting the transport block, a lower layer (e.g., PHY, MAC) of thewireless device may pass the transport block to a higher layer of thewireless device (e.g., MAC, RRC). The higher layer may parse thetransport block for a random-access preamble identity (RAPID) associatedwith the PRACH transmission. In an example, the higher layer mayidentify the RAPID in at least one random-access response (RAR) messageof the transport block. In an example, in response to the identifying,the higher layer may indicate an uplink grant (e.g., RAR uplink grant)to the lower layer of the wireless device.

In an example, the higher layer of the wireless device may indicate tothe lower layer (e.g., physical layer) of the wireless device totransmit a second PRACH in response to not detecting the DCI (e.g., DCIformat 1_0) with CRC scrambled by the corresponding RA-RNTI within thewindow.

In an example, the higher layer of the wireless device may indicate tothe lower layer (e.g., physical layer) of the wireless device totransmit a second PRACH in response to not receiving the transport blockin the PDSCH, correctly, within the window.

In an example, the higher layer of the wireless device may indicate tothe lower layer (e.g., physical layer) of the wireless device totransmit a second PRACH in response to not identifying the RAPIDassociated with the PRACH transmission from the wireless device.

In response to the higher layer indicating to the lower layer totransmit the second PRACH, the wireless device may transmit the secondPRACH within a first offset (e.g., N_(T,I)+0.75 msec) after the lastsymbol of the window

In an example, the wireless device may detect the DCI with CRC scrambledby the corresponding RA-RNTI.

In an example, the wireless device may detect/receive the transportblock in the PDSCH.

In an example, the wireless device may initiate the PRACH transmissionin response to receiving, from the base station, a PDCCH order.

In an example, the RAR UL grant may schedule a PUSCH transmission (e.g.,Msg3) from the wireless device. In an example, the RAR UL grant maycomprise at least one of: frequency hopping flag (e.g., 1 bit), afrequency resource allocation for the PUSCH transmission (e.g., 14 bit),a time resource allocation for the PUSCH transmission (e.g., 4 bit), MCS(e.g., 4 bit), TPC command for the PUSCH transmission (e.g., 3 bit), andCSI request (e.g., 1 bit).

In an example, the RAR UL grant in the at least one RAR message mayschedule a PUSCH transmission (e.g., Msg3). In an example, the wirelessdevice may transmit a second transport block in the PUSCH using a firstredundancy version (e.g., 0).

In an example, the base station may not provide the wireless device witha C-RNTI. In an example, the wireless device may be in RRC-IDLE mode. Inan example, the wireless device may be in RRC-INACTIVE mode. In anexample, when the wireless device transmits the PUSCH scheduled by theRAR UL grant, in response to not being provided with the C-RNTI, thewireless device may attempt to detect a third DCI (e.g., DCI format 1_0)with CRC scrambled by the TC-RNTI. In an example, the third DCI mayschedule a second PDSCH. In an example, the second PDSCH may comprise aUE contention resolution identity.

Example Bandwidth Parts (BWPs)

In an example, a wireless device may be configured with one or more BWPsfor a serving cell (e.g., PCell, SCell). In an example, the serving cellmay be configured with at most a first number (e.g., four) BWPs. In anexample, for an activated serving cell, there may be one active BWP atany point in time.

In an example, a BWP switching for a serving cell may be used toactivate an inactive BWP and deactivate an active BWP at a time. In anexample, the BWP switching may be controlled by a PDCCH indicating adownlink assignment or an uplink grant. In an example, the BWP switchingmay be controlled by an inactivity timer (e.g. bwp-InactivityTimer). Inan example, the BWP switching may be controlled by a MAC entity inresponse to initiating a Random Access procedure. In an example, the BWPswitching may be controlled by an RRC signalling.

In an example, in response to RRC (re-)configuration offirstActiveDownlinkBWP-Id (e.g., included in RRC signaling) and/orfirstActiveUplinkBWP-Id (e.g., included in RRC signaling) for a servingcell (e.g., SpCell), the wireless device may activate a DL BWP indicatedby the firstActiveDownlinkBWP-Id and/or an UL BWP indicated by thefirstActiveUplinkBWP-Id, respectively without receiving a PDCCHindicating a downlink assignment or an uplink grant. In an example, inresponse to an activation of an SCell, the wireless device may activatea DL BWP indicated by the firstActiveDownlinkBWP-Id and/or an UL BWPindicated by the firstActiveUplinkBWP-Id, respectively without receivinga PDCCH indicating a downlink assignment or an uplink grant.

In an example, for an active BWP of an activated serving cell (e.g.,PCell, SCell) configured with one or more BWPs, a wireless device mayperform, on the active BWP, at least one of: transmitting on UL-SCH onthe active BWP; transmitting on RACH on the active BWP if PRACHoccasions are configured; monitoring a PDCCH on the active BWP;transmitting, if configured, PUCCH on the active BWP; reporting CSI forthe active BWP; transmitting, if configured, SRS on the active BWP;receiving DL-SCH on the active BWP; (re-) initializing any suspendedconfigured uplink grants of configured grant Type 1 on the active BWPaccording to a stored configuration, if any, and to start in a symbolbased on some procedures.

In an example, for a deactivated BWP of an activated serving cellconfigured with one or more BWPs, a wireless device may not perform atleast one of: transmitting on UL-SCH on the deactivated BWP;transmitting on RACH on the deactivated BWP; monitoring a PDCCH on thedeactivated BWP; transmitting PUCCH on the deactivated BWP; reportingCSI for the deactivated BWP; transmitting SRS on the deactivated BWP,receiving DL-SCH on the deactivated BWP. In an example, for adeactivated BWP of an activated serving cell configured with one or moreBWPs, a wireless device may clear any configured downlink assignment andconfigured uplink grant of configured grant Type 2 on the deactivatedBWP; may suspend any configured uplink grant of configured Type 1 on thedeactivated (or inactive) BWP.

In an example, a wireless device may initiate a random-access procedure(e.g., contention-based random access, contention-free random access) ona serving cell (e.g., PCell, SCell).

In an example, a wireless device may receive, from a base station, oneor more configuration parameters for a two-step random-access (RA)procedure of a cell (e.g., PCell, SCell). For example, the one or moreconfiguration parameters may indicate at least one of following: one ormore RACH occasions (e.g., time-frequency resources), one or morerandom-access preambles (RAPs) (or RAP groups), preamble format, SSBinformation (e.g., a number of transmitting SSBs, downlink resourceallocation of SSB transmissions, transmission power of SSB transmission,and/or other information), one or more uplink radio resources (in termsof time, frequency, code/sequence/signature), and power controlparameters (e.g., cell and/or UE specific power adjustments used forcalculating received target power, inter-cell interference controlparameter that may be used as a scaling factor of pathloss measurement,reference signal power to calculate for pathloss measurement, and/or oneor more margins).

In an example, the two-step RA procedure may comprise a first uplink(UL) transmission of a RAP (e.g., two-step Msg1) of the one or more RAPsand a second UL transmission of one or more transport blocks (e.g.,FDM-ed, TDM-ed). In an example, in response to receiving the RAP and/orthe one or more transport blocks, the base station may transmit, to thewireless device, a two-step Msg2. The two-step Msg2 may comprise aresponse, e.g., random access response (RAR), corresponding to the firstUL transmission and/or the second UL transmission.

In an example, the two-step Msg2 may comprise at least one of following:a timing advance command indicating the TA value, a power controlcommand, an RAR UL grant (e.g., radio resource assignment, and/or MCS),a wireless device ID for contention resolution (e.g., a contentionresolution message), an RNTI (e.g., C-RNTI or TC-RNTI), and/or otherinformation. The two-step Msg2 (e.g., an RAR) may comprise a preambleidentifier corresponding to the RAP, a positive (ACK) or negativeacknowledgement (NACK) of a reception of the one or more transportblocks, and/or an indication of a successful decoding of the one or moretransport blocks. In an example, the wireless device may transmit one ormore second transport blocks based on the two-step Msg2.

In an example, in the two-step RA procedure, the wireless device maytransmit the RAP via at least one RACH resource of the one or more RACHoccasions indicated by the one or more configuration parameters. In anexample, the wireless device may transmit the one or more transportblocks via at least one UL radio resource of the one or more uplinkradio resources indicated by the one or more configuration parameters.

In an example, the one or more configuration parameters may indicate oneor more associations between the one or more uplink radio resources andthe one or more RAPs (or RAP groups). In an example, the one or moreconfiguration parameters may indicate one or more associations betweenthe one or more uplink radio resources and the one or more RACHoccasions.

In an example, the one or more associations may be one-to-one,multi-to-one, one-to-multi, and/or multi-to-multi between one or moreRAPs and one or more uplink radio resources. In an example, the one ormore associations may be one-to-one, multi-to-one, one-to-multi, and/ormulti-to-multi between one or more RACH occasions and one or more uplinkradio resources.

Based on the associations, a wireless device may determine which ULradio resource and/or which PRACH resource or RAP need to be selected.In an example, when the wireless device selects a RAP of the one or moreRAPs for a two-step RA procedure, based on the selection of the RAP andthe one or more associations, the wireless device may determine at leastone UL radio resource of the one or more uplink radio resources. In anexample, in response to the determining, the wireless device maytransmit the one or more transport blocks via the at least one UL radioresource for the two-step RA procedure.

In an example, the first transmission of the RAP may be overlapped intime and/or in frequency (partially or entirely) with the secondtransmission of the one or more transport blocks. In an example, thefirst transmission of the RAP may be multiplexed with the secondtransmission of the one or more transport blocks in time and/orfrequency domains

In an example, a wireless device may perform an LBT on an uplinkchannel. In an example, the wireless device may perform an uplinktransmission via the uplink channel in response to a success of the LBTfor the uplink channel. In an example, the success of the LBY for theuplink channel may comprise that the wireless device may determine theuplink channel idle (e.g., not being occupied by another wirelessdevice).

In an example, the wireless device may not perform an uplinktransmission (e.g., two-step Msg 1, preamble, one or more transportblocks) via the uplink channel in response to a failure of LBT for theuplink transmission. In an example, the failure of the LBT may comprisethat the wireless device determines that the uplink channel (e.g.,PRACH, PUSCH, PUCCH) for the uplink transmission is busy (occupied byanother wireless device).

In an example, the wireless device may perform a first LBT for the firstUL transmission of the RAP. In an example, the wireless device mayperform a second LBT for the second UL transmission of the one or moretransport blocks. In an example, the first LBT and the second LBT may bethe same (e.g., simultaneous, same frequency, same time, etc). In anexample, the first LBT and the second LBT may be different (e.g.,different times, frequency, etc).

In an example, the wireless device may determine a success of the firstLBT for the RAP. In an example, in response to the success of the firstLBT, the wireless device may perform the first UL transmission of theRAP via the RACH resource. In an example, in response to the success ofthe first LBT, the wireless device may not perform the second LBT forthe second UL transmission of the one or more transport blocks. In anexample, in response to the not performing the second LBT, the wirelessdevice may perform the second UL transmission of the one or moretransport blocks via the at least one UL radio resource when the firstLBT for the RAP is successful. This may be a case that PRACH and ULradio resources are allocated closely enough in time domain. In anexample, the wireless device may perform the first and the second ULtransmissions back to back in response to the being allocated closelyenough in time.

In an example, the wireless device may determine a success of the firstLBT (e.g., idle) for the RAP. In an example, in response to the successof the first LBT, the wireless device may perform the first ULtransmission of the RAP via the RACH resource and the second ULtransmission of the one or more transport blocks via the at least one ULradio resource.

In an example, the wireless device may determine a failure of the firstLBT (e.g., busy) for the RAP. In an example, in response to the failureof the first LBT, the wireless device may not perform the first ULtransmission of the RAP via the RACH resource and the second ULtransmission of the one or more transport blocks via the at least one ULradio resource.

In an example, a wireless device may receive, from a base station, oneor more messages (e.g. RRC connection reconfiguration message, or RRCconnection reestablishment message, or RRC connection setup message)comprising one or more configuration parameters for a cell (e.g., PCell,PSCell, SCell). In an example, the one or more configuration parametersmay comprise bandwidth part (BWP) configuration parameters for aplurality of downlink BWPs of the cell and a plurality of uplink BWPs ofthe cell.

In an example, the wireless device may operate in a paired spectrum(e.g., frequency division duplex (FDD)).

In an example, the one or more configuration parameters may furthercomprise downlink BWP specific indices for the plurality of downlinkBWPs and/or uplink BWP specific indices for the plurality of uplinkBWPs. In an example, each downlink BWP of the plurality of downlink BWPsmay be identified by a respective one downlink BWP specific index of thedownlink BWP specific indices (e.g., provided by a higher layerparameter bwp-ID). In an example, each uplink BWP of the plurality ofuplink BWPs may be identified by a respective one uplink BWP specificindex of the uplink BWP specific indices (e.g., provided by a higherlayer parameter bwp-ID).

In an example, at a time slot, the wireless device may operate on afirst downlink BWP of the plurality of downlink BWPs and a second uplinkBWP of the plurality of uplink BWPs of the cell. In response to theoperating, the wireless device may be, at the time slot, active on thefirst downlink BWP and the second uplink BWP for the cell. In anexample, at the time slot, the first downlink BWP and the second uplinkBWP may be an active downlink BWP and an active uplink BWP of the cell,respectively in response to the operating.

In an example, when the first downlink BWP is the active downlink BWPand the second uplink BWP is the active uplink BWP of the cell (e.g., atthe time slot), the wireless device may initiate a random-accessprocedure (e.g., contention-based random-access procedure,contention-free random-access procedure). The wireless device mayperform the random-access procedure on the first downlink BWP and thesecond uplink BWP.

In an example, the random-access procedure may be initiated for aninitial access from RRC_IDLE, an RRC Connection Re-establishmentprocedure, a handover, a DL or UL data arrival during RRC_CONNECTED whenUL synchronization status is “non-synchronized”, a transition fromRRC_INACTIVE, a time alignment establishment at SCell addition, a beamfailure recovery, or a request for other system information (SI).

In an example, the one or more configuration parameters may comprise oneor more PRACH resources on the second uplink BWP. In an example, the oneor more configuration parameters may comprise one or more RSs (e.g.,SS/PBCH blocks, CSI-RS). In an example, the one or more configurationparameters may further comprise one or more associations (orcorrespondence) between the one or more RSs and the one or more PRACHresources (e.g., the association may be one-to-one, one-to-many,many-to-one, etc). The association may be provided by configurationparameters (e.g., RACH-ConfigDedicated, CandidateBeamRSList,RACH-ConfigCommon, ra-ssb-OccasionMaskIndex, ra-OccasionList etc).

In an example, the performing the random-access procedure on the seconduplink BWP may comprise performing a random-access resource selection onthe second uplink BWP. In an example, the performing the random-accessresource selection may comprise selecting a first RS in the one or moreRSs. The first RS may be a first SS/PBCH block or a first CSI-RS. In anexample, based on the one or more associations, the first RS may beassociated with (or corresponding to) a PRACH resource of the one ormore PRACH resources configured on the second uplink BWP. The PRACHresource may comprise at least one preamble (associated withPREAMBLE_INDEX) and at least one PRACH occasion (e.g., time, frequency,code) on the second uplink BWP.

In an example, in response to the performing the random-access resourceselection, the wireless device may perform a random-access preambletransmission. In an example, in the random-access preamble transmission,the wireless device may transmit, in a first slot, the at least onepreamble via the at least one PRACH resource of the second uplink BWPfor the random-access procedure.

In an example, in response to transmitting the at least one preamble inthe first slot, the wireless device may start, from a second slot, aconfigured response window (e.g., ra-responseWindow). In an example, theconfigured response window may be configured by the one or moreconfiguration parameters (e.g., RACH-ConfigCommon,BeamFailureRecoveryConfig).

In an example, when the configured response window is running, thewireless device may monitor for a random-access response (RAR)corresponding to the at least one preamble. The monitoring for therandom-access response may comprise monitoring, for a DCI (e.g. adownlink assignment, an uplink grant), at least one PDCCH in the seconddownlink BWP of the cell (e.g., SpCell).

In an example, the DCI may be identified with CRC scrambled by a C-RNTIor MCS-C-RNTI of the wireless device. For example, the random-accessprocedure may be initiated for a beam failure recovery of the cell.

In an example, the DCI may be identified with CRC scrambled by aRA-RNTI.

In an example, an offset between the first slot and the second slot maybe fixed. In an example, the offset may be 4 slots.

In an example, the second slot may be at a first PDCCH occasion of thesecond downlink BWP from the end of the transmitting the at least onepreamble.

In an example, when the random-access procedure is initiated for a beamfailure recovery, in response to receiving the DCI (e.g., scrambled byC-RNTI or MCS-C-RNTI) on the at least one PDCCH in the second downlinkBWP of the cell, within the configured response window, therandom-access procedure (e.g., contention-free random-access procedure)for the beam failure recovery may be successfully completed.

In an example, the random-access response may comprise a first MACsubPDU with a random-access preamble identifier. In an example, therandom-access preamble identifier may be associated with (orcorresponding to) the at least one preamble (e.g., PREAMBLE_INDEX).

In an example, when the random-access procedure is not initiated for abeam failure recovery (e.g., contention-free random-access procedure forthe beam failure recovery), in response to receiving the DCI (e.g.,scrambled by RA-RNTI) in the at least one PDCCH of the second downlinkBWP of the cell, within the configured response window, and therandom-access preamble identifier being associated with (orcorresponding to) the at least one preamble, a reception of therandom-access response may be successfully completed.

In an example, when the random-access procedure is not initiated for abeam failure recovery and a reception of the random-access response issuccessfully completed, in response to receiving the DCI (e.g.,scrambled by RA-RNTI) on the at least one PDCCH in the second downlinkBWP of the cell, within the configured response window, therandom-access procedure (e.g., contention-free random-access procedure)may be successfully completed.

In an example, the configured response window may expire. In an example,the wireless device may not receive the DCI within the configuredresponse window. In response to the configured response window expiringand the wireless device not receiving the DCI (e.g., scrambled byC-RNTI) or a random-access response comprising the random-accesspreamble identifier being associated with (or corresponding to) the atleast one preamble, the wireless device may consider a reception of therandom-access response unsuccessful and may increment a preambletransmission counter variable (e.g., PREAMBLE_TRANSMISSION_COUNTER) byone.

In an example, in response to the incrementing, the preambletransmission counter variable may be equal to or greater than a preamblemaximum transmission parameter (e.g., RRC parameter preambleTransMax).

In an example, the cell may be an SpCell (e.g., PCell, PSCell). In anexample, the wireless device may transmit the at least one preamble onthe SpCell in response to the cell being the SpCell. In an example, thewireless device may indicate a problem of the random-access procedure toupper layers (e.g., RRC) in response to the preamble transmissioncounter variable being equal to or greater than the preamble maximumtransmission parameter.

In an example, the cell may be an SCell. In an example, the wirelessdevice may transmit the at least one preamble on the SCell in responseto the cell being the SCell. In an example, the wireless device maycomplete the random-access procedure unsuccessfully in response to thepreamble transmission counter variable being equal to or greater thanthe preamble maximum transmission parameter.

In an example, in response to the indicating the problem of therandom-access procedure to the upper layers (e.g., RRC), the upperlayers may trigger a radio link failure that may lead to prolongedrandom-access delay and degraded user experience.

In an example, in response to the incrementing, the preambletransmission counter variable may be less than the preamble maximumtransmission parameter plus one. In response to the preambletransmission counter variable being less than the preamble maximumtransmission parameter plus one, the wireless device may consider therandom-access procedure incomplete.

In an example, in response to the considering the random-accessprocedure incomplete, the wireless device may select a random back-offtime. The random back-off time may be selected according to a uniformdistribution between zero and a preamble back-off variable in the RAR.In an example, the wireless device may start a back-off timer with avalue indicated by the random back-off time in response to theselecting.

In an example, while the back-off timer is running, the wireless devicemay perform a second random-access resource selection. The wirelessdevice may select a second RS in the one or more RSs. In an example, thesecond RS may be a second SS/PBCH block or a second CSI-RS. In anexample, based on the one or more associations, the second RS may beassociated with (or corresponding to) a second PRACH resource of the oneor more PRACH resources configured on the second uplink BWP. The secondPRACH resource may comprise at least one second preamble and at leastone second PRACH occasion (e.g., time, frequency, code) on the seconduplink BWP. In an example, when the wireless device performs the secondrandom-access resource selection, the wireless device may perform asecond random-access preamble transmission. In an example, in the secondrandom-access preamble transmission, the wireless device may transmit,in a third slot, the at least one second preamble via the at least onesecond PRACH resource of the second uplink BWP for the random-accessprocedure.

In an example, in a contention-based two-step random-access procedure,PUSCH resources to transmit a MsgA payload of the contention-basedtwo-step random-access procedure may be shared among a plurality ofwireless devices. In an example, each wireless device of the pluralityof wireless devices may transmit, via the PUSCH resources, a MsgApayload for a respective contention-based two-step random-accessprocedure. Based on the PUSCH resources being shared, a wireless device,of the plurality of wireless devices, may not release the PUSCHresources in response to completing a contention-based two-steprandom-access procedure. Based on not releasing the PUSCH resources, thewireless device may transmit, via the PUSCH resources, a MsgA payloadfor a subsequent contention-based two-step random-access procedure.

In an example, in a contention-free two-step random-access procedure,PUSCH resources to transmit a MsgA payload of the contention-freetwo-step random-access procedure may be dedicated to a wireless device.Based on the PUSCH resources being dedicated, the PUSCH resources may becontention-free PUSCH resources. In an example, the wireless device mayinitiate a contention-free two-step random-access procedure (e.g., forhandover, for beam failure recovery procedure, etc). Based on theinitiating the contention-free two-step random-access procedure, thewireless device may transmit a random-access preamble viacontention-free random-access resources and a MsgA payload. The wirelessdevice may transmit the MsgA payload via the contention-free PUSCHresource(s). The wireless device may complete the contention-freetwo-step random-access procedure based on receiving a random-accessresponse. In an example, the wireless device may not release thecontention-free PUSCH resource(s) based on the completing. The wirelessdevice may use (or transmit via) the contention-free PUSCH resource(s)for subsequent random-access procedures.

In an example, based on the completing the contention-free two-steprandom-access procedure, the base station may allocate/assign thecontention-free PUSCH resource(s) to a second wireless device. This mayincrease the resource efficiency when the wireless device does not usethe contention-free PUSCH resource(s) for the subsequent random-accessprocedures for a long time. The contention-free PUSCH resource(s) notused by the wireless device may be allocated/assigned to the secondwireless device. Implementation of not releasing the contention-freePUSCH resource(s) based on the completing the contention-free two-steprandom-access procedure may not be efficient. For example, when thenumber of wireless devices in a cell is high, resource efficiency may beimportant to meet quality of service (QoS) demands of the wirelessdevices in the cell. When the wireless device does not release thecontention-free PUSCH resource(s) assigned/allocated to the secondwireless device, the wireless device and the second wireless device maytransmit via the contention-free PUSCH resource(s) resulting incollision. This may lead to unsuccessful reception of MsgA payload atthe base station, lowering the data rate, increasing the delay of asuccessful communication, increasing battery consumption due toretransmissions, etc. There is a need to implement an enhanced procedurefor the contention-free PUSCH resource(s) when a wireless devicecompletes a contention-free two-step random-access procedure.

In an example, the wireless device may release the contention-free PUSCHresource(s) during the contention-free two-step random-access procedure.In an example, the wireless device may release the contention-free PUSCHresource(s) after the contention-free two-step random-access procedureis completed. The wireless device may release the contention-free PUSCHresource(s) after a time duration after the contention-free two-steprandom-access procedure is completed. In an example, the wireless devicemay release the contention-free PUSCH resource(s) based on an indication(e.g., downlink control information indicating to release) from the basestation. There is a need to define at which point/condition to releasethe contention-free PUSCH resources. This may enable the base stationand the wireless device to be aligned on the usage of thecontention-free PUSCH resources. In an example, the base station may notmonitor the contention-free PUSCH resources for a MsgA reception whenthe wireless device releases the contention-free PUSCH resources. Thismay lead to power efficiency at the base station.

In an example embodiment, a wireless device may release thecontention-free PUSCH resource(s) based on the completing thecontention-free two-step random-access procedure. In an example, thewireless device may complete the contention-free two-step random-accessprocedure based on receiving a PDCCH scheduling a random-accessresponse. The PDCCH may be identified by a C-RNTI. The PDCCH may beidentified by a RA-RNTI. The PDCCH may be identified by a MSGB-RNTI. Inan example, the wireless device may complete the contention-freetwo-step random-access procedure based on a number of preambletransmissions reaching to a configured maximum number. Releasing thecontention-free PUSCH resource(s) may increase the resource efficiency,improve the battery consumption and reduce collisions.

FIG. 24 shows an example of a random-access procedure as per an aspectof an embodiment of the present disclosure.

In an example, a wireless device may receive, from a base station, oneor more configuration parameters for a two-step random-access (RA)procedure of a cell (e.g., PCell, SCell) at time T0 in FIG. 24. In anexample, the one or more configuration parameters may indicate one ormore PRACH resources (e.g., PRACH resources in FIG. 24).

In an example, the one or more PRACH resources may comprise one or morerandom-access preambles (RAPs). In an example, the one or more PRACHresources may comprise one or more RACH occasions (e.g., time/frequencyoccasion).

In an example, the one or more configuration parameters may indicate oneor more uplink radio resources (in terms of time, frequency,code/sequence/signature) for a MsgA payload transmission of the two-stepRA procedure. The one or more uplink radio resources are Uplinkresources in FIG. 24. In an example, the uplink radio resources may bePUSCH resources.

In an example, an uplink radio resource of the one or more uplink radioresources may indicate at least one time resource/occasion. In anexample, an uplink radio resource of the one or more uplink radioresources may indicate at least one frequency resource/occasion.

In an example, the one or more configuration parameters may indicate oneor more uplink grants. The one or more uplink grants may indicate one ormore uplink radio resources (in terms of time, frequency,code/sequence/signature). In an example, the one or more uplink grantsindicating the one or more uplink radio resources (or PUSCH resources)may comprise that an uplink grant of the one or more uplink grants mayindicate at least one time resource/occasion of the one or more uplinkradio resources (or PUSCH resources). In an example, the one or moreuplink grants indicating the one or more uplink radio resources maycomprise that an uplink grant of the one or more uplink grants mayindicate at least one frequency resource/occasion of the one or moreuplink radio resources.

In an example, the base station may broadcast one or more uplink radioresources (in terms of time, frequency, code/sequence/signature). Theone or more uplink radio resources are Uplink resources in FIG. 24. Inan example, in response to the broadcasting the one or more uplinkresources, a plurality of wireless devices (in the cell) including thewireless device may share the one or more uplink radio resources (orPUSCH resources).

In an example, the base station may broadcast one or more uplink grants.The one or more uplink grants may indicate one or more uplink radioresources (in terms of time, frequency, code/sequence/signature). Theone or more uplink radio resources are Uplink resources in FIG. 24. Inan example, in response to the broadcasting the one or more uplinkgrants, a plurality of wireless devices (in the cell) including thewireless device may share the one or more uplink grants. In an example,the one or more uplink grants indicating the one or more uplink radioresources may comprise that an uplink grant of the one or more uplinkgrants may indicate at least one time resource/occasion of the one ormore uplink radio resources. In an example, the one or more uplinkgrants indicating the one or more uplink radio resources may comprisethat an uplink grant of the one or more uplink grants may indicate atleast one frequency resource/occasion of the one or more uplink radioresources.

In an example, the one or more configuration parameters may indicate oneor more associations/mappings between the one or more uplink radioresources (or the one or more uplink grants) and the one or more PRACHresources. In an example, the one or more configuration parameters mayindicate one or more associations/mappings between the one or moreuplink radio resources (or the one or more uplink grants) and the one ormore RAPs of the one or more PRACH resources. In an example, the one ormore configuration parameters may indicate one or moreassociations/mappings between the one or more uplink radio resources (orthe one or more uplink grants) and the one or more RACH occasions of theone or more PRACH resources. In an example, the one or moreassociations/mappings may be one-to-one, multi-to-one, one-to-multi,and/or multi-to-multi.

In an example, in FIG. 25, PRACH resource 1 of the one or more PRACHresources is one-to-one associated/mapped with uplink resource 1 of theone or more uplink radio resources (or with uplink grant 1 of the one ormore uplink grants). In an example, in response to the one-to-oneassociation/mapping, when the wireless device selects the PRACH resource1 for a two-step random-access procedure, the wireless device selectsthe uplink resource 1 (indicated by the uplink grant 1) for an uplinktransmission of a transport block (e.g., PUSCH, Msg3). In an example,when the base station receives a transport block on the uplink resource1, based on the one-to-one association/mapping, the base station maydetermine that the wireless device selected the PRACH resource 1 for atwo-step random-access procedure.

In an example, in FIG. 25, PRACH resource 2 of the one or more PRACHresources is one-to-multi associated/mapped with uplink resource 2 ofthe one or more uplink radio resources (or with uplink grant 2 of theone or more uplink grants) and uplink resource 3 of the one or moreuplink radio resources (or with uplink grant 3 of the one or more uplinkgrants). In an example, in response to the one-to-multiassociation/mapping, when the wireless device selects the PRACH resource2 for a two-step random-access procedure, the wireless device selectsthe uplink resource 2 (indicated by the uplink grant 2) or the uplinkresource 3 (indicated by the uplink grant 3) for an uplink transmissionof a transport block (e.g., PUSCH, Msg3). In an example, when the basestation receives a transport block on the uplink resource 2 or on theuplink resource 3, based on the one-to-multi association/mapping, thebase station may determine that the wireless device selected the PRACHresource 2 for a two-step random-access procedure.

In an example, in FIG. 25, uplink resource 3 of the one or more uplinkradio resources (or uplink grant 3 of the one or more uplink grants) ismulti-to-one associated/mapped with PRACH resource 2 of the one or morePRACH resources and PRACH resource 3 of the one or more PRACH resources.In an example, in response to the multi-to-one association/mapping, whenthe wireless device selects the PRACH resource 2 or the PRACH resource 3for a two-step random-access procedure, the wireless device may selectthe uplink resource 3 (or the uplink grant 3 of the one or more uplinkgrants) for an uplink transmission of a transport block (e.g., PUSCH,Msg3). In an example, when the base station receives a transport blockon the uplink resource 3, based on the multi-to-one association/mapping,the base station may determine that the wireless device selected thePRACH resource 2 or the PRACH resource 3 for a two-step random-accessprocedure.

In an example, the wireless device may initiate a two-step random-accessprocedure (e.g., contention-free random-access procedure,contention-based random-access procedure) for the cell at time T1 inFIG. 24. In an example, the wireless device may perform a firstrandom-access resource selection in response to the initiating thetwo-step random-access procedure. In an example, the wireless device mayselect a random-access channel (PRACH) resource of the one or more PRACHresources for the first random-access selection. In an example, thePRACH resource may comprise at least one preamble. In an example, thePRACH resource may comprise at least one PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code).

In an example, when the wireless device performs the first random-accessresource selection for the two-step random-access procedure, based onthe one or more associations/mappings (e.g., in FIG. 25), the wirelessdevice may determine/select at least one UL radio resource (e.g., PUSCHresource) of the one or more uplink radio resources (or determine/selectat least one UL grant of the one or more uplink grants) for an uplinktransmission of a transport block (e.g., MsgA payload, Msg3, PUSCH). Inan example, the PRACH resource may be (e.g., one-to-one, one-to-multi,multi-to-one) associated/mapped with the at least one UL radio resource(or the at least one UL grant). In an example, at least one UL grant mayindicate the at least one UL radio resource. In an example, the at leastone UL radio resource may comprise at least one time resource/occasionand/or at least one frequency resource/occasion. In an example, thePRACH resource being associated/mapped with the at least one UL radioresource (or the at least one UL grant) may comprise the at least onepreamble of the PRACH resource being associated/mapped with the at leastone UL radio resource (or the at least one UL grant). In an example, thePRACH resource being associated/mapped with the at least one UL radioresource (or the at least one UL grant) may comprise the at least onePRACH occasion of the PRACH resource being associated/mapped with the atleast one UL radio resource (or the at least one UL grant).

In an example, based on the first random-access selection, the wirelessdevice may transmit, via the at least one PRACH occasion, the at leastone preamble for the two-step random-access procedure at time T2 in FIG.24.

In an example, in response to the determining/selecting the at least oneUL radio resource (or the at least one UL grant), the wireless devicemay transmit, via the at least one UL radio resource (e.g., a PUSCHresource), the transport block (e.g., MsgA payload) for the uplinktransmission for the two-step random-access procedure at time T3 in FIG.24. In an example, the at least one UL grant may indicate the at leastone UL radio resource.

In an example, the transmission of the at least one preamble may overlapin time and/or in frequency (partially or entirely) with the uplinktransmission of the transport block (e.g., FIG. 17B.). In an example,the at least one PRACH occasion may be multiplexed with the at least oneUL radio resource in time and/or frequency domains (e.g., TDM-ed,FDM-ed). In an example, when the at least one PRACH occasion ismultiplexed with the at least one UL radio resource in a frequencydomain, the wireless device may transmit the at least one preamble andthe at least one UL radio resource simultaneously (e.g., FIG. 17B, T2and T3 may be the same in FIG. 24).

In an example, when the at least one PRACH occasion is multiplexed withthe at least one UL radio resource in a time domain, the wireless devicemay transmit the at least one preamble and the transport block atdifferent times with a time gap (e.g., FIG. 17A, FIG. 17C, T2 and T3 maybe different in FIG. 24).

In an example, in response to the transmitting the at least one preambleand/or the transport block, the wireless device may monitor a PDCCH fora response (e.g., random-access response, two-step Msg2, MsgB), from thebase station. In an example, the response may be corresponding to the atleast one preamble. In an example, the response may be corresponding tothe transport block. In an example, the response may be corresponding tothe at least one preamble and the transport block.

In an example, the base station may detect the at least one preamble andthe transport block. In response to the detecting the at least onepreamble and the transport block, the response, from the base station,may be corresponding to the at least one preamble and the transportblock.

In an example, the base station may detect the at least one preamble. Inan example, the base station may not detect the transport block. Inresponse to the detecting the at least one preamble and not detectingthe transport block, the response, from the base station, may becorresponding to the at least one preamble.

In an example, the base station may not detect the at least onepreamble. In an example, the base station may detect the transportblock. In response to the not detecting the at least one preamble anddetecting the transport block, the response, from the base station, maybe corresponding to the transport block.

In an example, the response may comprise at least one of following: anRAR UL grant (e.g., radio resource assignment, and/or MCS), a wirelessdevice ID for contention resolution (e.g., a contention resolutionmessage), an RNTI (e.g., C-RNTI or TC-RNTI), and/or other information.In an example, the response may comprise a timing advance command (e.g.,Timing advance command MAC-CE) indicating a timing advance value. In anexample, the response (e.g., an RAR) may comprise a preamble identifiercorresponding to the at least one preamble, a positive (ACK) or negativeacknowledgement (NACK) of a reception of the transport block, and/or anindication of a successful decoding of the transport block.

In an example, the monitoring for the response may comprise attemptingto detect a DCI (e.g., DCI format 1_0) during a window (e.g.,ra-responseWindow). In an example, the one or more configurationparameters may indicate the window (e.g., Window in FIG. 24).

In an example, the monitoring for the response may comprise monitoring,for a DCI (e.g. a downlink assignment, an uplink grant), at least onePDCCH in the cell (e.g., SpCell). In an example, the DCI may comprise anuplink grant. In an example, the DCI may comprise a downlink assignment.

In an example, the DCI may be with CRC scrambled by a second RNTI. In anexample, the second RNTI may be RA-RNTI. In an example, the second RNTImay be a C-RNTI. In an example, the second RNTI may be a TC-RNTI. In anexample, the second RNTI may be a CS-RNTI. In an example, the secondRNTI may be a MCS-C-RNTI. In an example, the second RNTI may be aMSGB-RNTI (e.g., since the DCI is scheduling the response, which is alsonamed as MsgB).

In an example, the wireless device may detect the DCI (e.g., DCI format1_0) in the at least one PDCCH in the cell within the window at time T4in FIG. 24. In an example, the wireless device may detect a firsttransport block in a PDSCH. In an example, the DCI may schedule thefirst transport block in the PDSCH. In an example, in response to thedetecting the first transport block, a lower layer (e.g., PHY, MAC) ofthe wireless device may pass the first transport block to a higher layerof the wireless device (e.g., MAC, RRC). The higher layer may parse thefirst transport block for a random-access preamble identity (RAPID).

In an example, the wireless device may receive the responsecorresponding to the at least one preamble. In an example, receiving theresponse corresponding to the at least one preamble may comprise thatthe RAPID (in the first transport block) identifies the at least onepreamble. In an example, receiving the response corresponding to the atleast one preamble may comprise that the RAPID (in the first transportblock) indicates the at least one preamble. In an example, the DCIscheduling the response may have a CRC scrambled by the second RNTI(e.g., RA-RNTI). In an example, in response to the receiving theresponse corresponding to the at least one preamble, the wireless devicemay complete the reception of the response successfully.

In an example, the wireless device may receive the responsecorresponding to the transport block. In an example, receiving theresponse corresponding to the transport block may comprise that theresponse identifies a wireless ID (e.g., contention-resolution ID,wireless-specific/dedicated ID, random number selected by the wirelessdevice, etc). In an example, receiving the response corresponding to thetransport block may comprise that the response comprises an RNTI (e.g.,C-RNTI or TC-RNTI) of the wireless device. In an example, receiving theresponse corresponding to the transport block may comprise that the DCIscheduling the response has a CRC scrambled by the second RNTI (e.g.,C-RNTI) of the wireless device. In an example, the response may comprisea timing advance command (e.g., Timing advance command MAC-CE)indicating a timing advance value. In an example, receiving the responsecorresponding to the transport block may comprise that the responsecomprises an identifier corresponding to the transport block. In anexample, receiving the response corresponding to the transport block maycomprise that the response comprises an ACK/NACK for a reception of thetransport block. In an example, receiving the response corresponding tothe transport block may comprise that the response comprises anindication of a successful decoding of the transport block. In anexample, in response to the receiving the response corresponding to thetransport block, the wireless device may complete the reception of theresponse successfully.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, in response toreceiving the response corresponding to the at least one preamble, thetwo-step random-access procedure may be successfully completed.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, in response toreceiving the response corresponding to the transport block, thetwo-step random-access procedure may be successfully completed.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, in response toreceiving the response corresponding to the at least one preamble andthe transport block, the two-step random-access procedure may besuccessfully completed.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, in response toreceiving the response corresponding to at least one of the transmittedat least one preamble and the transport block, the two-steprandom-access procedure may be successfully completed.

In an example, the wireless device may determine that the two-steprandom access procedure is unsuccessfully completed. For example, whenthe wireless device does not receive the response corresponding to atleast one of the transmitted at least one preamble and the transportblock during the window, based on a maximum number of preambletransmissions (e.g., preambleTransMax configured by the one or moreconfiguration parameters), the wireless device may consider the two-steprandom-access procedure unsuccessfully completed. In an example, anumber of preamble transmissions may be equal to or greater than themaximum number of preamble transmissions.

In an example, the two-step random-access procedure may be acontention-free random-access procedure.

In an example, the base station may explicitly indicate/signal the oneor more PRACH resources for the contention-free random-access procedure(e.g., handover, system information request, PDCCH order, beam failurerecovery procedure). In an example, the base station may explicitlyindicate the one or more PRACH resources in response to the two-steprandom-access procedure being the contention-free random-accessprocedure (e.g., handover, system information request, PDCCH order, beamfailure recovery procedure).

In an example, for the explicit indication/signaling, the base stationmay provide the wireless device with the one or more PRACH resources bya higher layer parameter rach-ConfigDedicated. In an example, the one ormore configuration parameters may comprise the higher layer parameterrach-ConfigDedicated.

In an example, for the explicit indication/signaling, the base stationmay provide the wireless device with the one or more PRACH resources byan RRC signaling (e.g., BeamFailureRecoveryConfig, SI-SchedulingInfo), aDCI or a MAC CE.

In an example, the base station may explicitly indicate/signal (e.g., bya PDCCH order) the at least one preamble (e.g., ra-PreambleIndex) forthe contention-free random-access procedure. In an example, the basestation may explicitly indicate/signal (e.g., by a PDCCH order) the atleast one preamble (e.g., ra-PreambleIndex) in response to the two-steprandom-access procedure being the contention-free random-accessprocedure. In an example, for the explicit indication/signaling, thebase station may transmit, to the wireless device, a DCI (e.g., PDCCHorder) indicating the at least one preamble (e.g., ra-PreambleIndex).

In an example, when the wireless device completes the two-steprandom-access procedure (e.g., successfully or unsuccessfully), inresponse to the two-step random-access procedure being thecontention-free random-access procedure (e.g., initiated by handover,system information request, PDCCH order), the wireless device maydiscard the one or more PRACH resources. In an example, the base stationmay explicitly indicate/signal the one or more PRACH resources for thecontention-free random-access procedure. In an example, the wirelessdevice may not initiate the two-step random-access procedure (or thecontention-free random-access procedure) for a beam failure recoveryprocedure of the cell. In an example, when the wireless device discardsthe one or more PRACH resources, in response to the one or moreassociations/mappings between the one or more uplink radio resources (orthe one or more uplink grants) and the one or more PRACH resources, thewireless device may clear the one or more uplink radio resources (orclear the one or more uplink grants) at time T4 in FIG. 24.

In an example, in response to the completing the two-step random-accessprocedure (e.g., successfully or unsuccessfully) and the two-steprandom-access procedure being the contention-free random-accessprocedure (e.g., initiated by handover, system information request,PDCCH order), the wireless device may clear the one or more uplink radioresources (or clear the one or more uplink grants) at time T4 in FIG.24.

In an example, when the wireless device completes the two-steprandom-access procedure at time T4 in FIG. 24, in response to thetwo-step random-access procedure being the contention-free random-accessprocedure (e.g., initiated by handover, system information request,PDCCH order), the wireless device may discard the PRACH resource. In anexample, the base station may explicitly indicate/signal the at leastone preamble of the PRACH resource for the contention-free random-accessprocedure. In an example, the wireless device may not initiate thetwo-step random-access procedure (or the contention-free random-accessprocedure) for a beam failure recovery procedure of the cell. In anexample, when the wireless device discards the PRACH resource, inresponse to the PRACH resource being associated/mapped with the at leastone UL radio resource (or the at least one UL grant), the wirelessdevice may clear the at least one UL radio resource (or clear the atleast one UL grant) at time T4 in FIG. 24.

In an example, in response to the completing the two-step random-accessprocedure (e.g., successfully or unsuccessfully) and the two-steprandom-access procedure being the contention-free random-accessprocedure (e.g., initiated by handover, system information request,PDCCH order), the wireless device may clear the at least one UL radioresource (or clear the at least one UL grant) at time T4 in FIG. 24.

In an example, the base station may explicitly indicate/signal the oneor more uplink radio resources (or the one or more uplink grants) forthe contention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, the base station may explicitly indicate/signal the one ormore uplink radio resources (or the one or more uplink grants) inresponse to the two-step random-access procedure being thecontention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, for the explicit indication/signaling, the base station mayprovide the wireless device with the one or more uplink radio resources(or the one or more uplink grants) by an RRC signaling, a DCI or MAC-CE.

In an example, the base station may explicitly indicate/signal the atleast one UL radio resource (or the at least one UL grant) for thecontention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, the base station may explicitly indicate/signal the at leastone UL radio resource (or the at least one UL grant) in response to thetwo-step random-access procedure being the contention-free random-accessprocedure (e.g., handover, system information request, PDCCH order, beamfailure recovery procedure). In an example, for the explicitindication/signaling, the base station may provide the wireless devicewith the at least one UL radio resource (or the at least one UL grant)by an RRC signaling, a DCI or MAC-CE.

In an example, when the wireless device completes the two-steprandom-access procedure (e.g., successfully or unsuccessfully) and thetwo-step random-access procedure is the contention-free random-accessprocedure (e.g., initiated by handover, system information request,PDCCH order), the wireless device may clear the one or more uplink radioresources (or clear the one or more uplink grants) at time T4 in FIG. 24in response to the base station explicitly indicating/signalling the oneor more uplink radio resources (or the one or more uplink grants) forthe two-step random-access procedure. In an example, the wireless devicemay not initiate the two-step random-access procedure (or thecontention-free random-access procedure) for a beam failure recoveryprocedure of the cell.

In an example, when the wireless device completes the two-steprandom-access procedure (e.g., successfully or unsuccessfully) and thetwo-step random-access procedure is the contention-free random-accessprocedure (e.g., initiated by handover, system information request,PDCCH order), the wireless device may clear the at least one UL radioresource (or the at least one UL grant) at time T4 in FIG. 24 inresponse to the base station explicitly indicating/signaling the atleast one UL radio resource (or the at least one UL grant) for thetwo-step random-access procedure. In an example, the wireless device maynot initiate the two-step random-access procedure (or thecontention-free random-access procedure) for a beam failure recoveryprocedure of the cell.

In an example, the clearing the at least one UL radio resource (or theat least one UL grant) may comprise that the wireless device may nottransmit a transport block via the at least one UL radio resourceindicated by the at least one UL grant. In an example, the wirelessdevice may not transmit a transport block via the at least one UL radiowhen the wireless device initiates a new random-access procedure. In anexample, the base station may assign/allocated the at least one UL radioresource to a second wireless device. If a wireless device does notclear the at least one UL radio resource, the wireless device maytransmit a transport block via the at least one UL radio resourceresulting in a collision with the second wireless device. In an example,the clearing the at least one UL radio resource (or the at least one ULgrant) may comprise that the wireless device may not use the at leastone UL grant for an uplink transmission of a transport block. In anexample, the clearing the at least one UL radio resource (or the atleast one UL grant) may comprise releasing the at least one UL radioresource (or the at least one UL grant).

In an example, the clearing the one or more uplink radio resources (orclear the one or more uplink grants) may comprise that the wirelessdevice may not transmit a transport block via the one or more uplinkradio resources indicated by the one or more uplink grants. In anexample, the clearing the one or more uplink radio resources (or clearthe one or more uplink grants) may comprise that the wireless device maynot transmit a transport block via an uplink radio resource of the oneor more uplink radio resources indicated by an uplink grant of the oneor more uplink grants. In an example, the base station mayassign/allocated the one or more uplink radio resources to at least onewireless device. If a wireless device does not clear the one or moreuplink radio resources, the wireless device may transmit a transportblock via the one or more uplink radio resources resulting in acollision with the at least one wireless device. In an example, theclearing the one or more uplink radio resources (or the one or moreuplink grants) may comprise that the wireless device may not use the oneor more uplink grants for an uplink transmission of a transport block.In an example, the clearing the one or more uplink radio resources (orthe one or more uplink grants) may comprise releasing the one or moreuplink radio resources (or the one or more uplink grants).

In an example, the releasing an uplink resource (or an uplink grant) maycomprise that the wireless device releases a configuration of the uplinkresource (or the uplink grant). In an example, the base station mayreconfigure (or reschedule) the wireless device with the uplink resource(or the uplink grant) via an explicit message, PDCCH signaling, MAC CE,RRC message etc. to enable the wireless device to use the uplinkresource (or the uplink grant) again.

FIG. 26 shows an example flowchart of a random-access procedure as peran aspect of an embodiment of the present disclosure.

FIG. 27 shows an example of a random-access procedure as per an aspectof an embodiment of the present disclosure.

In an example, the step at time T0 in FIG. 27 is the same as the step attime T0 in FIG. 24. The discussions for the step at time T0 in FIG. 24apply to the step at time T0 in FIG. 27.

In an example, a wireless device may receive, from a base station, oneor more configuration parameters for a two-step random-access (RA)procedure of a cell (e.g., PCell, SCell) at time T0 in FIG. 27. In anexample, the one or more configuration parameters may indicate one ormore PRACH resources (e.g., PRACH resources in FIG. 27). In an example,the one or more configuration parameters may indicate one or more uplinkradio resources (or one or more uplink grants). The one or more uplinkradio resources are Uplink resources in FIG. 27.

In an example, a higher (or upper) layer (e.g., RRC, MAC) of thewireless device may request, from a lower layer (e.g., MAC, PHY) of thewireless device, a reset of a MAC entity of the wireless device (e.g.,MAC reset request in FIG. 27) at time T1 in FIG. 27.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, the base stationmay explicitly (e.g., by a higher layer parameter rach-ConfigDedicated,RRC signaling, BeamFailureRecoveryConfig, SI-SchedulingInfo, DCI, MACCE, etc) indicate/signal the one or more PRACH resources for thecontention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, the base stationmay explicitly indicate/signal the one or more PRACH resources inresponse to the two-step random-access procedure being thecontention-free random-access procedure.

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, the base stationmay explicitly indicate/signal (e.g., by a PDCCH order) the at least onepreamble (e.g., ra-PreambleIndex) for the contention-free random-accessprocedure. In an example, the base station may explicitlyindicate/signal the at least one preamble in response to the two-steprandom-access procedure being the contention-free random-accessprocedure.

In an example, when the higher layer (e.g., RRC, MAC) of the wirelessdevice requests, from the lower layer (e.g., MAC, PHY) of the wirelessdevice, the reset of the MAC entity, in response to the base stationexplicitly indicating/signalling the one or more PRACH resources for thetwo-step random-access procedure (e.g., the contention-freerandom-access procedure initiated by e.g., handover, system informationrequest, PDCCH order, beam failure recovery procedure), the wirelessdevice may discard the one or more PRACH resources. In an example, whenthe wireless device discards the one or more PRACH resources, inresponse to the one or more associations/mappings between the one ormore uplink radio resources (or the one or more uplink grants) and theone or more PRACH resources, the wireless device may clear the one ormore uplink radio resources (or clear the one or more uplink grants) attime T1 in FIG. 27.

In an example, in response to the higher layer (e.g., RRC, MAC) of thewireless device requesting, from the lower layer (e.g., MAC, PHY) of thewireless device, the reset of the MAC entity and the base stationexplicitly indicating/signalling the one or more PRACH resources for thetwo-step random-access procedure, the wireless device may clear the oneor more uplink radio resources (or clear the one or more uplink grants)at time T1 in FIG. 27.

In an example, when the higher layer (e.g., RRC, MAC) of the wirelessdevice requests, from the lower layer (e.g., MAC, PHY) of the wirelessdevice, the reset of the MAC entity, in response to the base stationexplicitly indicating/signalling the at least one preamble of the PRACHresource for the two-step random-access procedure (e.g., thecontention-free random-access procedure initiated by e.g., handover,system information request, PDCCH order, beam failure recoveryprocedure), the wireless device may discard the PRACH resource. In anexample, when the wireless device discards the PRACH resource, inresponse to the PRACH resource being associated/mapped with the at leastone UL radio resource (or the at least one UL grant), the wirelessdevice may clear the at least one UL radio resource (or clear the atleast one UL grant) at time T1 in FIG. 27.

In an example, in response to the higher layer (e.g., RRC, MAC) of thewireless device requesting, from the lower layer (e.g., MAC, PHY) of thewireless device, the reset of the MAC entity and the base stationexplicitly indicating/signalling the at least one preamble of the PRACHresource for the two-step random-access procedure, the wireless devicemay clear the at least one UL radio resource (or clear the at least oneUL grant) at time T1 in FIG. 27.

In an example, the base station may explicitly indicate/signal the oneor more uplink radio resources (or the one or more uplink grants) forthe contention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, the base station may explicitly indicate/signal the one ormore uplink radio resources (or the one or more uplink grants) inresponse to the two-step random-access procedure being thecontention-free random-access procedure. In an example, for the explicitindication/signaling, the base station may provide the wireless devicewith the one or more uplink radio resources (or the one or more uplinkgrants) by an RRC signaling, a DCI or MAC-CE.

In an example, the base station may explicitly indicate/signal the atleast one UL radio resource (or the at least one UL grant) for thecontention-free random-access procedure (e.g., handover, systeminformation request, PDCCH order, beam failure recovery procedure). Inan example, the base station may explicitly indicate/signal the at leastone UL radio resource (or the at least one UL grant) in response to thetwo-step random-access procedure being the contention-free random-accessprocedure. In an example, for the explicit indication/signaling, thebase station may provide the wireless device with the at least one ULradio resource (or the at least one UL grant) by an RRC signaling, a DCIor MAC-CE.

In an example, when the higher layer (e.g., RRC, MAC) of the wirelessdevice requests, from the lower layer (e.g., MAC, PHY) of the wirelessdevice, the reset of the MAC entity, the wireless device may clear theone or more uplink radio resources (or clear the one or more uplinkgrants) at time T1 in FIG. 27 in response to the base station explicitlyindicating/signalling the one or more uplink radio resources (or the oneor more uplink grants) for the two-step random-access procedure (e.g.,the contention-free random-access procedure initiated by e.g., handover,system information request, PDCCH order, beam failure recoveryprocedure).

In an example, when the higher layer (e.g., RRC, MAC) of the wirelessdevice requests, from the lower layer (e.g., MAC, PHY) of the wirelessdevice, the reset of the MAC entity, the wireless device may clear theat least one UL radio resource (or the at least one UL grant) at time T1in FIG. 27 in response to the base station explicitlyindicating/signalling the at least one UL radio resource (or the atleast one UL grant) for the two-step random-access procedure (e.g., thecontention-free random-access procedure initiated by e.g., handover,system information request, PDCCH order, beam failure recoveryprocedure).

FIG. 28 shows an example flowchart of a random-access procedure as peran aspect of an embodiment of the present disclosure.

FIG. 29 shows an example of a random-access procedure as per an aspectof an embodiment of the present disclosure.

In an example, a wireless device may receive, from a base station, oneor more configuration parameters for a two-step random-access (RA)procedure of a BWP (e.g., UL BWP) of a cell (e.g., PCell, SCell) at timeT0 in FIG. 29. In an example, the one or more configuration parametersmay indicate one or more PRACH resources (e.g., PRACH resources in FIG.29). In an example, the one or more configuration parameters mayindicate one or more uplink radio resources (or one or more uplinkgrants) for the BWP of the cell. The one or more uplink radio resourcesare Uplink resources in FIG. 29.

In an example, the one or more configuration parameters may indicate oneor more associations/mappings between the one or more uplink radioresources (or the one or more uplink grants) and the one or more PRACHresources (e.g., the associations/mappings discussed in FIG. 24 and FIG.25).

In an example, the two-step random-access procedure may be acontention-free random-access procedure. In an example, the base stationmay explicitly (e.g., RRC signaling, BeamFailureRecoveryConfig,SI-SchedulingInfo, MAC CE, DCI) indicate/signal the one or more PRACHresources for the contention-free random-access procedure (e.g.,handover, system information request, PDCCH order, beam failure recoveryprocedure). In an example, the base station may explicitlyindicate/signal the one or more PRACH resources in response to thetwo-step random-access procedure being the contention-free random-accessprocedure.

In an example, the BWP may be an active BWP of the cell (e.g., the firstdownlink BWP as the active downlink BWP of the cell, the second uplinkBWP as the active uplink BWP of the cell). In an example, the wirelessdevice may switch from the BWP to a second BWP of the cell. In anexample, the switching may be initiated in response to receiving a DCIindicating the second BWP, or receiving an RRC signaling indicating thesecond BWP, or an expiry of a BWP inactivity timer of the cell, orinitiating a random-access procedure. In an example, the switching fromthe BWP to the second BWP may comprise activating the second BWP of thecell. In an example, the switching from the BWP to the second BWP maycomprise deactivating the BWP of the cell. In an example, the switchingfrom the BWP to the second BWP may comprise setting the second BWP as asecond active BWP of the cell.

In an example, when the wireless device deactivates the BWP, thewireless device may keep/suspend the one or more PRACH resources on theBWP at time T1 in FIG. 29. In an example, in response to thekeeping/suspending, the wireless device may use the one or more PRACHresources (e.g., configured for a beam failure recovery procedure) whenthe BWP is activated again.

In an example, when the wireless device deactivates the BWP, thewireless device may not discard the one or more PRACH resources on theBWP at time T1 in FIG. 29. In an example, in response to the notdiscarding, the wireless device may use the one or more PRACH resources(e.g., configured for a beam failure recovery procedure) when the BWP isactivated again.

In an example, in response to the deactivating the BWP, the wirelessdevice may suspend the one or more uplink radio resources (or the one ormore uplink grants) on the BWP at time T1 in FIG. 29.

In an example, when the wireless device deactivates the BWP and does notdiscard the one or more PRACH resources on the BWP, in response to the(existing) one or more associations/mappings between the one or moreuplink radio resources (or the one or more uplink grants) and the one ormore PRACH resources, the wireless device may suspend the one or moreuplink radio resources (or the one or more uplink grants) on the BWP attime T1 in FIG. 29.

In an example, in response to the deactivating the BWP, the wirelessdevice may suspend the one or more uplink radio resources (or the one ormore uplink grants) on the BWP at time T1 in FIG. 29. In an example, thewireless device may use the one or more PRACH resources for a procedureof the cell (e.g., a beam failure recovery procedure of the cell). In anexample, based on the (existing) one or more associations/mappingsbetween the one or more uplink radio resources (or the one or moreuplink grants) and the one or more PRACH resources, the wireless devicemay use the one or more uplink radio resources (or the one or moreuplink grants) for the procedure.

In an example, if the wireless device does not suspend the one or moreuplink radio resources, the wireless device may not use the one or moreuplink radio resources (or the one or more uplink grants)associated/mapped with/to the one or more PRACH resources when the BWPis activated again. In an example, when the wireless device does notsuspend the one or more uplink radio resources, the base station maytransmit a configuration message, to the wireless device, to reconfigurethe one or more uplink radio resources (or the one or more uplinkgrants) increasing the overhead and signaling messages/exchange.

In an example, the second BWP may be the second active BWP of the cell.In an example, the wireless device may switch from the second BWP to theBWP. In an example, the switching may be initiated in response toreceiving a second DCI indicating the BWP, or receiving a second RRCsignaling indicating the BWP, or an expiry of a BWP inactivity timer ofthe cell or initiating a second random-access procedure. In an example,the switching from the second BWP to the BWP may comprise activating theBWP of the cell. In an example, the switching from the second BWP to theBWP may comprise deactivating the second BWP of the cell. In an example,the switching from the second BWP to the BWP may comprise setting theBWP as the active BWP of the cell.

In an example, in response to the activating the BWP, the wirelessdevice may initialize or reinitialize the (suspended) one or more uplinkradio resources (or the one or more uplink grants) on the BWP at time T1in FIG. 29.

In an example, the suspending the one or more uplink radio resources (orthe one or more uplink grants) on the BWP may comprise that the wirelessdevice keeps a configuration of the one or more uplink radio resources(or the one or more uplink grants) on the BWP. In an example, thesuspending the one or more uplink radio resources (or the one or moreuplink grants) on the BWP may comprise that the wireless device is notallowed to use the one or more uplink radio resources (or the one ormore uplink grants) on the BWP when the BWP is deactivated. In anexample, the wireless device may resume using the one or more uplinkradio resources (or the one or more uplink grants) on the BWP inresponse to the BWP being activated (e.g., being the active BWP of thecell).

In an example, a wireless device may trigger a scheduling request (SR)for requesting UL-SCH resource when the wireless device has a new uplinktransmission. In an example, a base station may transmit, to thewireless device, at least one message comprising parameters indicatingzero, one or more SR configurations. An SR configuration may comprise aset of PUCCH resources for an SR transmission on one or more BWPs and/oron one or more cells. An SR configuration may correspond to one or morelogical channels. A logical channel may be mapped to zero or one SRconfiguration configured by the at least one message. An SRconfiguration of a logical channel (LCH) that triggers a buffer statusreport (BSR) may be considered as a corresponding SR configuration for atriggered SR.

In an example, for an SR configuration, the at least one message mayfurther comprise one or more parameters indicating at least one of: a SRprohibit timer; a maximum number of SR transmission (e.g., sr-TransMax);a parameter indicating a periodicity and offset of an SR transmission;and/or PUCCH resources. In an example, the SR prohibit timer may be aduration during which the wireless device may be not allowed to transmitthe SR. In an example, the maximum number of SR transmission may be atransmission number for which the wireless device may be allowed totransmit the SR at most.

In an example, a wireless device may maintain a SR transmission counter(e.g., SR_COUNTER) associated with an SR configuration.

In an example, if an SR of an SR configuration is triggered, and thereare no other SRs pending corresponding to the (same) SR configuration, awireless device may set the SR_COUNTER of the SR configuration to afirst value (e.g., 0).

In an example, if there is at least one valid PUCCH resource for the(pending) SR, a wireless device may determine an SR transmissionoccasion on the at least one valid PUCCH resource of the PUCCHresources. In an example, if the at least one valid PUCCH resource forthe SR transmission occasion does not overlap with a measurement gap;and if the at least one valid PUCCH resource for the SR transmissionoccasion does not overlap with an uplink shared channel (UL-SCH)resource; if the SR_COUNTER is less than the maximum number of SRtransmission, the wireless device may increment the SR_COUNTER (e.g., byone), instruct the physical layer of the wireless device to signal theSR on the at least one valid PUCCH resource for the SR. The physicallayer of the wireless device may transmit a PUCCH on the at least onevalid PUCCH resource for the SR. The wireless device may monitor a PDCCHfor detecting a DCI for uplink grant in response to transmitting thePUCCH.

In an example, if a wireless device receives one or more uplink grantswhich may accommodate all pending data available for transmission, thewireless device may cancel the pending SR.

In an example, if the wireless device may not receive one or more uplinkgrants which may accommodate all pending data available for the newuplink transmission, the wireless device may repeat one or more actionscomprising: determining at least one valid PUCCH resource; checkingwhether the SR prohibit timer is running; whether the SR_COUNTER isequal or greater than the maximum number of SR transmission;incrementing the SR_COUNTER, transmitting the SR and starting the SRprohibit timer; monitoring a PDCCH for one or more uplink grants.

In an example, the SR_COUNTER may indicate a number being equal to orgreater than the maximum number of SR transmission.

In response to the SR_COUNTER indicating the number being equal to orgreater than the maximum number of SR transmission, the wireless devicemay clear one or more configured uplink grants (e.g., configured grantType 1, configured grant Type 2).

In response to the SR_COUNTER indicating the number being equal to orgreater than the maximum number of SR transmission, the wireless devicemay clear the one or more uplink grants. In an example, the base stationmay configure the one or more uplink grants for the two-steprandom-access procedure.

In an example, the one or more uplink radio resources (or the one ormore uplink grants) may be specific/dedicated to the wireless device. Inan example, the one or more uplink radio resources (or the one or moreuplink grants) being specific/dedicated to the wireless device maycomprise that the one or more uplink radio resources (or the one or moreuplink grants) are not shared by another wireless device (different thanthe wireless device). In an example, the wireless device may use the oneor more uplink resources for a two-step random-access procedure.

In an example, in response to the SR_COUNTER indicating the number beingequal to or greater than the maximum number of SR transmission, thewireless device may not clear the one or more uplink grants.

In an example, in response to the SR_COUNTER indicating the number beingequal to or greater than the maximum number of SR transmission, thewireless device may initiate a second random access procedure on asecond cell (e.g., SpCell), and/or cancel the pending SR.

In an example, if the wireless device clears the one or more uplinkgrants in response to the SR_COUNTER indicating the number being equalto or greater than the maximum number of SR transmission, the wirelessdevice may not use the one or more uplink radio resources (or the one ormore uplink grants) for the second random-access procedure. In anexample, the wireless device may not initiate a two-step random-accessprocedure in response to the clearing the one or more uplink radioresources (or the one or more uplink grants). In an example, the secondrandom-access procedure may not be a two-step random-access procedure.This may result in a latency to acquire an uplink grant. This mayintroduce a delay. In an example, the second random-access procedure maybe a four-step random-access procedure, which may have a longer durationthan a two-step random-access procedure.

In an example, a wireless device may receive, e.g., from a base station,configuration parameters of one or more cells. The configurationparameters may indicate periodic uplink PUSCH resources for a bundle ofa configured uplink grant for a cell. The bundle of the configureduplink grant may be for an ultra-reliable and low latency communication(uRLLC) service, a V2X service, an IoT service, and/or the like. Forexample, when the wireless device has a transport block (TB) for anuRLLC service, the wireless device may transmit the TB via an uplinkresource (of an uplink grant) of the periodic uplink resources of thebundle of the configured uplink grant. In an example, based on theconfigured uplink grant being for the uRLLC service, the configureduplink grant may be mapped to a logical channel with a high logicalchannel priority. Based on the configured uplink grant being mapped tothe logical channel with the high logical channel priority, atransmission of the TB for an uRLLC service via the uplink resource mayhave a higher priority. For example, the wireless device may transmitthe TB with the higher priority when the uplink resource to transmit theTB overlaps with another uplink resource of another uplink transmissionwith a lower priority. Configured grants provide periodic resources tothe wireless device when the wireless device is in connected mode andits uplink signals are time aligned. In an example, configured grantsmay not be suitable when the wireless device is not time aligned and/orwhen traffic pattern is not suitable for transmission via configuredgrant resources.

In an example, the wireless device may receive, e.g., from a basestation, configuration parameters indicate PUSCH resources fortransmission of msgA payloads for two-step random-access procedures. Forexample, when the wireless device initiates a two-step random-accessprocedure, the wireless device may select/determine a PUSCH resource,among the PUSCH resources, to transmit msgA payload of the two-steprandom-access procedure. PUSCH resources for transmission of msgApayloads may be used for transmission of one or more packets of anultra-reliable and low latency communication (uRLLC) service, a V2Xservice, an IoT service, and/or the like. msgA payloads are transmittedwith a preamble and can be transmitted even when the UE is not timealigned. In an example, PUSCH resources for transmission of msgApayloads may not be suitable when the wireless device is time alignedand/or when traffic pattern is not suitable for transmission via msgApayload.

In an example embodiment, a base station may provide an enhancedconfiguration for a UE, in which the periodic uplink resources of theconfigured uplink grant and the PUSCH resources of the two-steprandom-access procedure are configured on the same cell. This enhancedconfiguration provides additional resources to the wireless device andthe base station to transmit short and/or periodic packets depending ontraffic type, radio link quality, and/or time alignment. In an exampleembodiment, configuration parameters may indicate periodic uplink PUSCHresources for the bundle of a configured uplink grant and PUSCHresources for transmission of msgA payloads for two-step random-accessprocedures on the same cell. This configuration may increase signalingoverhead; however, it enhances uplink transmission opportunities and/orreduces transmission delay.

In an example, the base station may configure the periodic uplinkresources of the configured uplink grant and the PUSCH resources of thetwo-step random-access procedure such that they do not overlap in time.This may limit flexibility in configuring both a bundle of configureduplink grant and the PUSCH resources of the two-step random-accessprocedure for the same cell in order to simplify UE processes for uplinktransmissions. However, configuring non-overlapping resources mayincrease the waiting time (or transmission delay) of the wireless deviceto transmit for the configured uplink grant and/or the two-steprandom-access procedure. Configuring non-overlapping resources may alsoreduce uplink spectral efficiency (e.g. more resources are dedicated toconfigured grant and msgA payload).

In an example embodiment, a base station may provide an enhancedconfiguration for a UE, in which overlapping radio resources areconfigured for the periodic uplink resources of the configured uplinkgrant and the PUSCH resources of the two-step random-access procedure onthe same cell. This enhanced configuration may reduce transmission delayand increase spectral efficiency, since the base station has moreflexibility on how to configure these resources.

In an example, the base station may configure overlapping resources fora bundle of configured uplink grant and the PUSCH resources of thetwo-step random-access procedure for the same cell. In an example, thewireless device may have a TB to transmit for an uRLLC service via afirst PUSCH resource of the periodic uplink resources of the configureduplink grant. During the same time period, the wireless device mayinitiate a two-step random-access procedure. The wireless device mayselect a PUSCH resource, among the PUSCH resources, for transmission ofa msgA payload of the two-step random-access procedure. The PUSCHresource may overlap in time (e.g., at least one symbol) with the firstPUSCH resource of the configured uplink grant. Transmission of twosignals via overlapping radio resources of a cell may require additionaltransmit power amplifier and transceiver management capability (e.g.including multiple parallel transceiver modules) and may increase uplinkinterference. In an example, transmitting the TB for the configureduplink grant in parallel with transmission or without transmission ofmsgA payload may result uplink timing misalignment, increasedinterference to other wireless devices and/or cells. This may degradethe performance of other wireless devices. There is a need to implementan enhanced procedure when an uplink resource of the configured uplinkgrant overlaps in time with a PUSCH resource of a msgA payloadtransmission of the two-step random-access procedure. Exampleembodiments provides an enhanced mechanism for uplink transmission whentransmission of msgA payload via the PUSCH resource and transmission ofthe TB via the uplink grant of the configured uplink grant overlap intime.

In an example embodiment, the wireless device may determine that a PUSCHduration of a configured uplink grant overlaps with a transmission of aMsgA payload via the first PUSCH resource of the same cell. Based on thedetermining, the wireless device may ignore the configured uplink grantby not transmitting via a PUSCH resource of the configured uplink grant.The wireless device may prioritize the transmission of the msgA payloadwhen an uplink resource an uplink grant of a bundle of the configureduplink grant overlaps in time with a PUSCH resource of the msgA payloadtransmission of the two-step random-access procedure. This enhancedmechanism may result in dropping transmission of a TB via an uplinkgrant of the configured uplink grant; however, it increases uplinktransmission efficiency as described in the specification.

In an example, transmission of msgA payload may enable the wirelessdevice to obtain uplink timing adjustment from the base station whiletransmitting an uplink packet. In an example implementation, thewireless device may obtain, via the two-step random-access procedure, aTA value enabling the wireless device to be uplink synchronized with thebase station. Based on being uplink synchronized, the wireless devicemay transmit, via the next non-overlapping PUSCH resource of theconfigured uplink grant, the TB for the configured uplink grant with anaccurate timing advance without incurring interference to other cellsand/or wireless devices. This may improve the performance of cellularsystems (decreased uplink interference, increased successful receptionof uplink transmissions, decreased uplink retransmissions, decreasedpower consumption due to decreased retransmissions, etc).

FIG. 30 and FIG. 31 show examples of a random-access procedure as per anaspect of an embodiment of the present disclosure. FIG. 32 and FIG. 33show example flowcharts of a random-access procedure disclosed in FIG.30 and FIG. 31, respectively.

In an example, the steps at time T0 and T1 in FIG. 30 and in FIG. 31 arethe same as the steps at time T0 and T1 in FIG. 24. The discussions forthe steps at time T0 and T1 in FIG. 24 apply to the steps at time T0 andT1 in FIG. 30 and in FIG. 31.

In an example, a wireless device may receive, from a base station, oneor more configuration parameters for a two-step random-access (RA)procedure of a cell (e.g., PCell, SCell) at time T0 in FIG. 30 and inFIG. 31. In an example, the one or more configuration parameters mayindicate one or more PRACH resources (e.g., PRACH resources in FIG. 30and in FIG. 31).

In an example, the one or more configuration parameters may indicate oneor more uplink radio resources (Uplink (PUSCH) resources in FIG. 30 andin FIG. 31). For example, in FIG. 30 and in FIG. 31, the one or moreuplink radio resources are Uplink resource-1, Uplink resource-2, andUplink resource-3. In an example, an uplink radio resource of the one ormore uplink radio resources may indicate at least one frequencyresource/occasion.

In an example, the one or more configuration parameters may indicate oneor more uplink grants (Uplink grants in FIG. 30 and in FIG. 31). Forexample, in FIG. 30 and in FIG. 31, the one or more uplink grants areUplink grant-1, Uplink grant-2, and Uplink grant-3. The one or moreuplink grants may indicate the one or more uplink radio resources. In anexample, the one or more uplink grants indicating the one or more uplinkradio resources may comprise that an uplink grant of the one or moreuplink grants may indicate at least one time resource/occasion of theone or more uplink radio resources. In an example, the one or moreuplink grants indicating the one or more uplink radio resources maycomprise that an uplink grant of the one or more uplink grants mayindicate at least one frequency resource/occasion of the one or moreuplink radio resources. In an example, in FIG. 30 and in FIG. 31, Uplinkgrant-n may indicate Uplink resource-n, n=1, 2, 3.

In an example, the one or more configuration parameters may indicate oneor more associations/mappings between the one or more uplink radioresources (or the one or more uplink grants) and the one or more PRACHresources (e.g., the associations/mappings discussed in FIG. 24 and FIG.25).

In an example, the wireless device may initiate a two-step random-accessprocedure (e.g., contention-free random-access procedure,contention-based random-access procedure) for the cell at time T1 inFIG. 30 and in FIG. 31.

In an example, the wireless device may perform a first random-accessresource selection in response to the initiating the two-steprandom-access procedure. In an example, the wireless device may select arandom-access channel (PRACH) resource of the one or more PRACHresources for the first random-access selection. In an example, thePRACH resource may comprise at least one preamble. In an example, thePRACH resource may comprise at least one PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code).

In an example, when the wireless device performs the first random-accessresource selection for the two-step random-access procedure, based onthe one or more associations/mappings (e.g., in FIG. 25), the wirelessdevice may determine/select at least one UL radio resource of the one ormore uplink radio resources (or determine/select at least one UL grantof the one or more uplink grants) for an uplink transmission of atransport block (e.g., Msg3, PUSCH). In an example, the PRACH resourcemay be (e.g., one-to-one, one-to-multi, multi-to-one) associated/mappedwith the at least one UL radio resource (or the at least one UL grant).In an example, the at least one UL grant may indicate the at least oneUL radio resource. In an example, the at least one UL radio resource maycomprise at least one time resource/occasion and/or at least onefrequency resource/occasion. In an example, the PRACH resource beingassociated/mapped with the at least one UL radio resource (or the atleast one UL grant) may comprise the at least one preamble of the PRACHresource being associated/mapped with the at least one UL radio resource(or the at least one UL grant). In an example, the PRACH resource beingassociated/mapped with the at least one UL radio resource (or the atleast one UL grant) may comprise the at least one PRACH occasion of thePRACH resource being associated/mapped with the at least one UL radioresource (or the at least one UL grant).

In an example, when the wireless device determines/selects, for thetwo-step random-access procedure, the at least one UL grant (e.g.,Uplink grant-2 in FIG. 30 and FIG. 31) indicating the at least one ULradio resource (e.g., Uplink resource-2 in FIG. 30 and FIG. 31), thewireless device may determine that the at least one UL radio resource ofthe at least one UL grant overlaps with a second UL radio resource(e.g., second PUSCH resource in FIG. 30 and FIG. 31) of a second ULgrant (e.g., second uplink grant in FIG. 30 and in FIG. 31). In anexample, the overlapping may be in time (e.g., at least one symbol, atleast one slot, at least one subframe). In an example, the at least oneUL radio resource may be a first PUSCH resource.

In an example, the second UL radio resource may not overlap in time withthe at least one PRACH occasion of the PRACH resource. In an example,the second UL radio resource may not overlap with the at least one PRACHoccasion of the PRACH resource in at least one symbol (e.g., OFDMsymbol). In an example, the second UL radio resource may not overlapwith the at least one PRACH occasion of the PRACH resource in at leastone slot. In an example, the second UL radio resource may not overlapwith the at least one PRACH occasion of the PRACH resource in at leastone subframe.

In an example, when the wireless device determines/selects the at leastone UL grant (e.g., Uplink grant-2 in FIG. 30 and FIG. 31) indicatingthe at least one UL radio resource (e.g., Uplink resource-2 in FIG. 30and FIG. 31), the wireless device may determine that a first duration ofthe at least one UL radio resource overlaps with a second duration of asecond UL radio resource (e.g., second PUSCH resource in FIG. 30 and inFIG. 31) of a second UL grant (e.g., second uplink grant in FIG. 30 andin FIG. 31). In an example, the overlapping (e.g., overlap in FIG. 30and in FIG. 31) may be in time (e.g., at least one symbol, at least oneslot, at least one subframe). In an example, the at least one UL radioresource may be a first PUSCH resource.

In an example, the wireless device may receive the second UL grant on atleast one PDCCH for the cell. In an example, the second UL grant may bea dynamic UL grant.

In an example, the wireless device may receive the second UL grant in arandom-access response for the cell.

In an example, the second UL grant may be a configured uplink grant(e.g., configured grant Type 1, configured grant Type 2) for the cell.In an example, the second UL grant may be a part of a bundle of aconfigured uplink grant (e.g., configured grant Type 1, configured grantType 2) for the cell.

In an example, the second UL grant may schedule a second uplinktransmission of a second transport block on the second UL radioresource.

In an example, in response to the determining the at least one UL radioresource of the at least one UL grant overlapping with the second ULradio resource of the second UL grant, the wireless device may ignorethe second UL grant (e.g., Second uplink grant in FIG. 30) at time T2 inFIG. 30.

In an example, in response to the determining the first duration of theat least one UL radio resource overlapping with the second duration ofthe second UL radio resource of the second UL grant, the wireless devicemay ignore the second UL grant (e.g., Second uplink grant in FIG. 30) attime T2 in FIG. 30.

In an example, the ignoring the second UL grant may comprise nottransmitting the second transport block via the second UL radio resourceindicated by the second UL grant. In an example, the ignoring the secondUL grant may comprise dropping the second transmission of the secondtransport block. In an example, the ignoring the second UL grant maycomprise transmitting, via the at least one UL radio resource (e.g.,Uplink resource-2 in FIG. 30) indicated by the at least one UL grant,the transport block for the two-step random-access procedure.

In an example, in response to the determining the at least one UL radioresource of the at least one UL grant overlapping with the second ULradio resource of the second UL grant, the wireless device may ignorethe at least one UL grant (e.g., Uplink grant-2 in FIG. 31) at time T2in FIG. 31.

In an example, in response to the determining the first duration of theat least one UL radio resource overlapping with the second duration ofthe second UL radio resource of the second UL grant, the wireless devicemay ignore the at least one UL grant (e.g., Uplink grant-2 in FIG. 31)at time T2 in FIG. 31.

In an example, the ignoring the at least one UL grant may comprisetransmitting, via the second UL radio resource (e.g., second PUSCHresource in FIG. 31) indicated by the second UL grant, the secondtransport block for the second uplink transmission. In an example, theignoring the at least one UL grant may comprise not transmitting, viathe at least one UL radio resource (e.g., Uplink resource-2 in FIG. 31)indicated by the at least one UL grant, the transport block for thetwo-step random-access procedure. In an example, the ignoring the atleast one UL grant may comprise dropping the uplink transmission of thetransport block.

In an example, the second UL grant may accommodate the second transportblock for the second uplink transmission and the transport block for theuplink transmission of the two-step random-access procedure. In anexample, when the wireless device ignores the at least one UL grant, thewireless device may transmit, via the second UL radio resource indicatedby the second UL grant, the second transport block and the transportblock in response to the second UL grant accommodating the secondtransport block and the transport block.

In an example, in response to the determining the at least one UL radioresource (e.g., Uplink resource-2 in FIG. 30) of the at least one ULgrant (e.g., Uplink grant-2 in FIG. 30) overlapping with the second ULradio resource (e.g., second PUSCH resource in FIG. 30) of the second ULgrant (e.g., second uplink grant in FIG. 30), the wireless device mayoverride the second UL grant with the at least one UL grant at time T2in FIG. 30.

In an example, in response to the determining the first duration of theat least one UL radio resource (e.g., Uplink resource-2 in FIG. 30)overlapping with the second duration of the second UL radio resource(e.g., second PUSCH resource in FIG. 30) of the second UL grant, thewireless device may override the second UL grant with the at least oneUL grant at time T2 in FIG. 30.

In an example, the overriding the second UL grant with the at least oneUL grant may comprise not transmitting, via the second UL radio resource(e.g., second PUSCH resource in FIG. 30) indicated by the second ULgrant, the second transport block for the second uplink transmission. Inan example, the overriding the second UL grant with the at least one ULgrant may comprise dropping the second transmission of the secondtransport block. In an example, the overriding the second UL grant withthe at least one UL grant may comprise transmitting, via the at leastone UL radio resource (e.g., Uplink resource-2 in FIG. 30) indicated bythe at least one UL grant, the transport block for the two-steprandom-access procedure.

In an example, in response to the determining the at least one UL radioresource (e.g., Uplink resource-2 in FIG. 31) of the at least one ULgrant (e.g., Uplink grant-2 in FIG. 31) overlapping with the second ULradio resource (e.g., second PUSCH resource in FIG. 31) of the second ULgrant (e.g., second uplink grant in FIG. 31), the wireless device mayoverride the at least one UL grant with the second UL grant at time T2in FIG. 31.

In an example, in response to the determining the first duration of theat least one UL radio resource (e.g., Uplink resource-2 in FIG. 31)overlapping with the second duration of the second UL radio resource(e.g., second PUSCH resource in FIG. 31) of the second UL grant (e.g.,second uplink grant in FIG. 31), the wireless device may override the atleast one UL grant with the second UL grant at time T2 in FIG. 31.

In an example, the overriding the at least one UL grant with the secondUL grant may comprise transmitting, via the second UL radio resourceindicated by the second UL grant, the second transport block for thesecond uplink transmission. In an example, the overriding the at leastone UL grant with the second UL grant may comprise not transmitting, viathe at least one UL radio resource indicated by the at least one ULgrant, the transport block for the two-step random-access procedure. Inan example, the overriding the at least one UL grant with the second ULgrant may comprise dropping the uplink transmission of the transportblock.

In an example, the second UL grant may accommodate the second transportblock for the second uplink transmission and the transport block for theuplink transmission of the two-step random-access procedure. In anexample, when the wireless device overrides the at least one UL grantwith the second UL grant, the wireless device may transmit, via thesecond UL radio resource indicated by the second UL grant, the secondtransport block and the transport block in response to the second ULgrant accommodating the second transport block and the transport block.

In an example, the wireless device may receive the second UL grant in aDCI. The DCI may be with CRC scrambled with a RNTI (e.g., RA-RNTI,C-RNTI or CS-RNTI) of the wireless device. In an example, when the atleast one UL radio resource of the at least one UL grant overlaps withthe second UL radio resource of the second UL grant, the wireless devicemay be required to transmit the at least one UL radio resource indicatedby the at least one UL grant and the second UL radio resource indicatedby the second UL grant concurrently on the cell (e.g., SpCell).

In an example, when the wireless device may not transmit the at leastone UL radio resource indicated by the at least one UL grant and thesecond UL radio resource indicated by the second UL grant concurrentlyon the cell, the wireless device may continue with the second UL grantfor the RNTI of the wireless device at time T2 in FIG. 31.

In an example, the continuing with the second UL grant for the RNTI maycomprise transmitting, via the second UL radio resource indicated by thesecond UL grant, the second transport block for the second uplinktransmission. In an example, the continuing with the second UL grant forthe RNTI may comprise not transmitting, via the at least one UL radioresource indicated by the at least one UL grant, the transport block forthe two-step random-access procedure. In an example, the continuing withthe second UL grant for the RNTI may comprise dropping the uplinktransmission of the transport block.

In an example, the second UL grant may accommodate the second transportblock for the second uplink transmission and the transport block for theuplink transmission of the two-step random-access procedure. In anexample, when the wireless device continues with the second UL grant forthe RNTI, the wireless device may transmit, via the second UL radioresource indicated by the second UL grant, the second transport blockand the transport block in response to the second UL grant accommodatingthe second transport block and the transport block.

In an example, when the wireless device may not transmit the at leastone UL radio resource indicated by the at least one UL grant and thesecond UL radio resource indicated by the second UL grant concurrentlyon the cell, the wireless device may continue with the at least one ULgrant at time T2 in FIG. 30.

In an example, the continuing with the at least one UL grant maycomprise not transmitting, via the second UL radio resource indicated bythe second UL grant, the second transport block for the second uplinktransmission. In an example, the continuing with the at least one ULgrant may comprise dropping the second uplink transmission of the secondtransport block. In an example, the continuing with the at least one ULgrant may comprise transmitting, via the at least one UL radio resourceindicated by the at least one UL grant, the transport block for thetwo-step random-access procedure.

In an example, when the at least one UL radio resource of the at leastone UL grant overlaps with the second UL radio resource of the second ULgrant, the wireless device may ignore the second UL grant. In anexample, the wireless device may be uplink unsynchronized. In anexample, the wireless device may initiate the two-step random-accessprocedure to be uplink synchronized. In an example, the wireless devicemay obtain a timing advance value (required for uplink synchronization)in the two-step random-access procedure. In an example, the obtainingthe timing advance value may have a higher priority than the seconduplink transmission for the second transport block via the second ULradio resource. In an example, the second uplink transmission for thesecond transport block may be for a data transmission. In response tothe transmitting the second transport block when the wireless device isuplink unsynchronized, the decoding performance may deteriorate. In anexample, transmitting the second transport block when the wirelessdevice is uplink unsynchronized may result in inter-symbol interferenceor inter-user interference. In an example, ignoring the second UL grantand transmitting the transport block via the at least one UL radioresource for the two-step random-access procedure to obtain thetiming-advance value may improve the performance.

In an example, when the at least one UL radio resource of the at leastone UL grant overlaps with the second UL radio resource of the second ULgrant, the wireless device may ignore the at least one UL grant. In anexample, the wireless device may initiate the two-step random-accessprocedure to be uplink synchronized. In an example, the wireless devicemay obtain a timing advance value in the two-step random-accessprocedure. In an example, the wireless device may operate in asmall-cell. In response to the operating in the small-cell, theobtaining the timing advance value may have a less priority than thesecond uplink transmission for the second transport block via the secondUL radio resource. In an example, the second uplink transmission for thesecond transport block may be for a data transmission. In an example,the second uplink transmission may be for an URLLC operation. In anexample, ignoring the at least one UL grant and transmitting the secondtransport block via the second UL radio resource may improve reduce thedelay/latency of data transmission.

FIG. 34 is an example of a random-access procedure as per an aspect ofan example embodiment of the present disclosure. According to an exampleembodiment, at time T0, a wireless device may receive one or more radioresource control (RRC) messages. The one or more RRC messages maycomprise one or more configuration parameters of a cell. The one or moreconfiguration parameters may indicate physical uplink shared channel(PUSCH) resources for transmissions of message A (MsgA) payloads oftwo-step random-access procedures of the cell (e.g., PUSCH resources inFIG. 34, PUSCH resource-1 for MsgA, PUSCH resource-2 for

MsgA, PUSCH resource-3 for MsgA in FIG. 34). The wireless device mayinitiate a two-step random-access procedure for the cell at time T1. Afirst PUSCH resource of the PUSCH resources may be selected based oninitiating the two-step random-access procedure for the cell. Adetermination may be made that a PUSCH duration of a configured uplinkgrant (e.g., UL grant in FIG. 34) overlaps with a transmission of a MsgApayload via the first PUSCH resource (e.g., at time T2). Based on thedetermination, the configured uplink grant may be ignored by nottransmitting via a second PUSCH resource of the configured uplink grant(e.g., at time T2). The one or more configuration parameters mayindicate a bundle of configured uplink grant (e.g., Configured uplinkgrant at time T0 or UL grants in FIG. 34).

FIG. 35 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3510, a wireless device may receive a bundleof a configured uplink grant of a cell. At 3520, a determination may bemade that a physical uplink shared channel (PUSCH) duration of an uplinkgrant of the bundle of the configured uplink grant overlaps with atransmission of a message A (MsgA) payload of a two-step random-accessprocedure of the cell. At 3530, based on the determination, the uplinkgrant may be ignored by not transmitting via a second PUSCH resource ofthe uplink grant.

According to an example embodiment, a wireless device may receive one ormore radio resource control (RRC) messages. The one or more RRC messagesmay comprise one or more configuration parameters of a cell. The one ormore configuration parameters may indicate physical uplink sharedchannel (PUSCH) resources for transmissions of message A (MsgA) payloadsof two-step random-access procedures of the cell. A first PUSCH resourceof the PUSCH resources may be selected based on initiating a two-steprandom-access procedure for the cell. A determination may be made that aPUSCH duration of a configured uplink grant overlaps with a transmissionof a MsgA payload via the first PUSCH resource. Based on thedetermination, the configured uplink grant may be ignored by nottransmitting via a second PUSCH resource of the configured uplink grant.

According to an example embodiment, a determination may be made that athird PUSCH resource of a second configured uplink grant does notoverlap with a second transmission of a second MsgA payload of a secondtwo-step random-access procedure of the cell. Based on thedetermination, the wireless device may transmit via the third PUSCHresource of the second configured uplink grant.

According to an example embodiment, the configured uplink grant may be aType 1 configured uplink grant. According to an example embodiment, theconfigured uplink grant may be a Type 2 configured uplink grant.

According to an example embodiment, the configured uplink grant may be apart of a bundle of a configured uplink grant. According to an exampleembodiment, the one or more configuration parameters may indicate thebundle of the configured uplink grant. According to an exampleembodiment, the configured uplink grant may be an uplink grant of thebundle of the configured uplink grant.

According to an example embodiment, the PUSCH duration overlapping withthe transmission of the MsgA payload via the first PUSCH resource maycomprise that the PUSCH duration overlaps with a first duration of thetransmission of the MsgA payload via the first PUSCH resource.

According to an example embodiment, the cell may be an unlicensed cell.

According to an example embodiment, the one or more configurationparameters may indicate, for the two-step random-access procedure, oneor more physical random-access channel (PRACH) resources. According toan example embodiment, the one or more configuration parameters mayindicate, for the two-step random-access procedure, one or more mappingsbetween the one or more PRACH resources and the PUSCH resources.According to an example embodiment, the one or more mappings may beone-to-one. According to an example embodiment, the one or more mappingsmay be many-to-one. According to an example embodiment, the one or moremappings may be one-to-many. According to an example embodiment, a PRACHresource of the one or more PRACH resources may be selected for thetwo-step random-access procedure. According to an example embodiment,the PRACH resource may comprise a preamble. According to an exampleembodiment, the PRACH resource may comprise a PRACH occasion. Accordingto an example embodiment, the selecting the first PUSCH resource may bebased on the one or more mappings. According to an example embodiment,the first PUSCH resource may be selected based on the PRACH resourcebeing mapped to the first PUSCH resource. According to an exampleembodiment, the PRACH resource being mapped to the first PUSCH resourcemay comprise that the PRACH occasion of the PRACH resource is mapped tothe first PUSCH resource. According to an example embodiment, the PRACHresource being mapped to the first PUSCH resource may comprise that thepreamble of the PRACH resource is mapped to the first PUSCH resource.According to an example embodiment, the PUSCH duration may not overlapwith the PRACH occasion.

According to an example embodiment, the MsgA payload may be transmittedvia the first PUSCH resource based on the ignoring the configured uplinkgrant.

According to an example embodiment, the two-step random-access proceduremay be a contention-free random-access procedure. According to anexample embodiment, the two-step random-access procedure may be acontention-based random-access procedure.

According to an example embodiment, the PUSCH duration overlapping withthe transmission of the MsgA payload may comprise that the PUSCHduration overlaps with the transmission of the MsgA payload in at leastone symbol or in at least one slot or in at least one subframe.

According to an example embodiment, a wireless device may receive one ormore radio resource control (RRC) messages. The one or more RRC messagesmay comprise one or more configuration parameters of a cell. The one ormore configuration parameters may indicate physical uplink sharedchannel (PUSCH) resources for transmissions of message A (MsgA) payloadsof two-step random-access procedures of the cell. A first PUSCH resourceof the PUSCH resources may be selected based on initiating a two-steprandom-access procedure for the cell. A determination may be made that aPUSCH duration of an uplink grant of a bundle of a configured uplinkgrant overlaps with a transmission of a MsgA payload via the first PUSCHresource. Based on the determination, the uplink grant may be ignored bynot transmitting via a second PUSCH resource of the uplink grant.

According to an example embodiment, a wireless device may select a firstphysical uplink shared channel (PUSCH) resource for transmission of amessage A (MsgA) payload of a two-step random-access procedure of acell. A determination may be made that a PUSCH duration of an uplinkgrant of a bundle of a configured uplink grant overlaps with thetransmission of the MsgA payload via the first PUSCH resource. Based onthe determination, the uplink grant may be ignored by not transmittingvia a second PUSCH resource of the uplink grant.

According to an example embodiment, a wireless device may determine thata physical uplink shared channel (PUSCH) duration of an uplink grant ofa bundle of a configured uplink grant overlaps with a transmission of amessage A (MsgA) payload of a two-step random-access procedure of acell. Based on the determining, the uplink grant may be ignored by nottransmitting via a second PUSCH resource of the uplink grant.

According to an example embodiment, a wireless device may receive abundle of a configured uplink grant of a cell. A determination may bemade that a physical uplink shared channel (PUSCH) duration of an uplinkgrant of the bundle of the configured uplink grant overlaps with atransmission of a message A (MsgA) payload of a two-step random-accessprocedure of the cell. Based on the determination, the uplink grant maybe ignored by not transmitting via a second PUSCH resource of the uplinkgrant.

According to an example embodiment, a determination may be made that athird PUSCH resource of a second uplink grant of the bundle of theconfigured uplink grant does not overlap with a second transmission of asecond MsgA payload of a second two-step random-access procedure of thecell. Based on the determination, the wireless device may transmit viathe third PUSCH resource.

FIG. 36 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3610, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. At 3620, the MsgA payload may betransmitted, via a first PUSCH resource of the PUSCH resources, for thetwo-step random-access procedure. At 3630, a determination may be madethat the two-step random-access procedure is completed. At 3640, basedon the determination, the PUSCH resources may be released.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. The MsgA payload may betransmitted, via a first PUSCH resource of the PUSCH resources, for thetwo-step random-access procedure. A determination may be made that thetwo-step random-access procedure is completed. At 3640, based on thedetermination, the PUSCH resources may be released.

According to an example embodiment, the completing the two-steprandom-access procedure may comprise receiving a first physical downlinkcontrol channel (PDCCH), for a first random-access response, identifiedby a cell Radio Network Temporary Identifier (C-RNTI). According to anexample embodiment, the completing the two-step random-access proceduremay comprise receiving a second PDCCH, for a second random-accessresponse, identified by a Radio Network Temporary Identifier (RNTI).According to an example embodiment, the completing the two-steprandom-access procedure may comprise a preamble transmission counterreaching a preamble maximum transmission. According to an exampleembodiment, the RNTI may be message B RNTI (MSGB-RNTI).

According to an example embodiment, the one or more configurationparameters may indicate one or more physical random-access channel(PRACH) resources. According to an example embodiment, the one or morePRACH resources may be discarded based on the determination that thetwo-step random-access procedure is completed. According to an exampleembodiment, the releasing the PUSCH resources may be further based onthe discarding the one or more PRACH resources.

According to an example embodiment, a PRACH resource of the one or morePRACH resources may be selected for the two-step random-accessprocedure. The PRACH resource may comprise a preamble. The PRACHresource may comprise a PRACH occasion. According to an exampleembodiment, the preamble may be transmitted via the PRACH occasion forthe two-step random-access procedure. According to an exampleembodiment, the receiving the second PDCCH for the second random-accessresponse may comprise receiving the second random-access responsescheduled by the second PDCCH. According to an example embodiment, thereceiving the second random-access response may comprise receiving thesecond random-access response corresponding to the preamble. Accordingto an example embodiment, the second random-access responsecorresponding to the preamble may comprise that a random-access preambleidentity in the second random-access response identifies the preamble.

According to an example embodiment, the one or more configurationparameters may indicate one or more mappings between the one or morePRACH resources and the PUSCH resources. According to an exampleembodiment, the one or more mappings may be one-to-one. According to anexample embodiment, the one or more mappings may be many-to-one.According to an example embodiment, the one or more mappings may beone-to-many. According to an example embodiment, the first PUSCHresource may be selected based on the one or more mappings. The PRACHresource may be mapped to the first PUSCH resource. According to anexample embodiment, the PRACH resource being mapped to the first PUSCHresource may comprise that the PRACH occasion of the PRACH resource ismapped to the first PUSCH resource. According to an example embodiment,the PRACH resource being mapped to the first PUSCH resource may comprisethat the preamble of the PRACH resource is mapped to the first PUSCHresource.

According to an example embodiment, the completing the two-steprandom-access procedure may comprise receiving a first PDCCH, for afirst random-access response, identified by a C-RNTI. According to anexample embodiment, the completing the two-step random-access proceduremay comprise a preamble transmission counter reaching a preamble maximumtransmission. According to an example embodiment, the receiving thefirst PDCCH for the first random-access response may comprise receivingthe first random-access response scheduled by the first PDCCH. Accordingto an example embodiment, the first random-access response may comprisea timing advance command indicating a timing advance value. According toan example embodiment, the first PDCCH may comprise an uplink grant.

According to an example embodiment, the cell may be an unlicensed cell.

According to an example embodiment, the two-step random-access proceduremay be a contention-free two-step random-access procedure. According toan example embodiment, the contention-free two-step random-accessprocedure may not be initiated for a beam failure recovery procedure ofthe cell.

According to an example embodiment, the releasing the PUSCH resourcesmay comprise not transmitting, via a PUSCH resource of the PUSCHresources, a MsgA payload. According to an example embodiment, thereleasing the PUSCH resources may comprise releasing a configuration ofthe PUSCH resources. According to an example embodiment, the releasingthe PUSCH resources may comprise releasing the one or moreconfigurations parameters indicating the PUSCH resources. According toan example embodiment, one or more second messages comprising one ormore second configuration parameters may be received after the releasingthe configuration. The one or more second configuration parameters mayindicate second PUSCH resources for transmission of a second MsgApayload of a second two-step random-access procedure of the cell.According to an example embodiment, the second MsgA payload may betransmitted, via a second PUSCH resource of the second PUSCH resources,for the second two-step random-access procedure.

According to an example embodiment, the releasing the PUSCH resourcesmay comprise stopping transmitting, via a PUSCH resource of the PUSCHresources, a MsgA payload.

According to an example embodiment, the one or more configurationparameters may indicate the preamble maximum transmission.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. The MsgA payload may betransmitted, via a first PUSCH resource of the PUSCH resources, for thetwo-step random-access procedure. The PUSCH resources may be releasedbased on receiving a first physical downlink control channel (PDCCH),for a first random-access response, identified by a cell Radio NetworkTemporary Identifier (C-RNTI). The PUSCH resources may be released basedon receiving a second PDCCH, for a second random-access response,identified by a message B Radio Network Temporary Identifier(MSGB-RNTI). The PUSCH resources may be released based on a preambletransmission counter reaching a preamble maximum transmission.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. The MsgA payload may betransmitted, via a first PUSCH resource of the PUSCH resources, for thetwo-step random-access procedure. The PUSCH resources may be releasedbased on receiving a first physical downlink control channel (PDCCH),for a first random-access response, identified by a cell Radio NetworkTemporary Identifier (C-RNTI). The PUSCH resources may be released basedon a preamble transmission counter reaching a preamble maximumtransmission.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. A determination may be made that aradio resource control (RRC) layer of the wireless device requestsresetting a medium access control (MAC) layer of the wireless device.Based on the determination, the MAC layer may be reset. The PUSCHresources may be released based on the MAC layer being reset.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate physical uplink shared channel (PUSCH) resourcesfor transmission of a message A (MsgA) payload of a two-steprandom-access procedure of the cell. A medium access control (MAC) layerof the wireless device may be reset. The MAC layer may be reset based ona request by a radio resource control (RRC) layer of the wirelessdevice. The PUSCH resources may be released based on the MAC layer beingreset.

According to an example embodiment, a wireless device may receive one ormore messages. The one or more messages may comprise one or moreconfiguration parameters of a cell. The one or more configurationparameters may indicate, for transmission of message A (MsgA) payloadsof two-step random-access procedures of the cell, physical uplink sharedchannel (PUSCH) resources on a first uplink bandwidth part (BWP) of thecell. The first uplink BWP of the cell may be activated. A MsgA payloadmay be transmitted, via a first PUSCH resource of the PUSCH resources,for a two-step random-access procedure of the cell. The first uplink BWPmay be deactivated. The first uplink BWP may be deactivated based onswitching from the first uplink BWP to a second uplink BWP of the cell.The PUSCH resources may be suspended based on the deactivating.

According to an example embodiment, the suspending the PUSCH resourcesmay comprise keeping a configuration of the PUSCH resources.

According to an example embodiment, the two-step random-access proceduremay be initiated for a beam failure recovery procedure of the cell.

According to an example embodiment, the first uplink BWP may beactivated based on switching from the second uplink BWP to the firstuplink BWP. According to an example embodiment, the suspended PUSCHresources may be initialized based on the activating the first uplinkBWP. According to an example embodiment, the initializing the suspendedPUSCH resources may comprise resume using the PUSCH resources for atwo-step random-access procedure of the cell.

According to an example embodiment, based on the deactivating the firstuplink BWP, the wireless device may stop transmitting, via a PUSCHresource of the PUSCH resources, a MsgA payload for a two-steprandom-access procedure of the cell.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). A base station may comprise multiple sectors. When thisdisclosure refers to a base station communicating with a plurality ofwireless devices, this disclosure may refer to a subset of the totalwireless devices in a coverage area. This disclosure may refer to, forexample, a plurality of wireless devices of a given LTE or 5G releasewith a given capability and in a given sector of the base station. Theplurality of wireless devices in this disclosure may refer to a selectedplurality of wireless devices, and/or a subset of total wireless devicesin a coverage area which perform according to disclosed methods, and/orthe like. There may be a plurality of base stations or a plurality ofwireless devices in a coverage area that may not comply with thedisclosed methods, for example, because those wireless devices or basestations perform based on older releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed to one or more of the various embodiments.

If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayalso refer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, various embodiments are disclosed. Limitations,features, and/or elements from the disclosed example embodiments may becombined to create further embodiments within the scope of thedisclosure.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Furthermore, many features presented above are described as beingoptional through the use of “may” or the use of parentheses. For thesake of brevity and legibility, the present disclosure does notexplicitly recite each and every permutation that may be obtained bychoosing from the set of optional features. However, the presentdisclosure is to be interpreted as explicitly disclosing all suchpermutations. For example, a system described as having three optionalfeatures may be embodied in seven different ways, namely with just oneof the three possible features, with any two of the three possiblefeatures or with all three of the three possible features.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (i.e.hardware with a biological element) or a combination thereof, all ofwhich may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or Lab VIEWMathScript.Additionally, it may be possible to implement modules using physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware comprise:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed using languages such as assembly, C,C++ or the like. FPGAs, ASICs and CPLDs are often programmed usinghardware description languages (HDL) such as VHSIC hardware descriptionlanguage (VHDL) or Verilog that configure connections between internalhardware modules with lesser functionality on a programmable device. Theabove mentioned technologies are often used in combination to achievethe result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the scope. In fact, after reading the abovedescription, it will be apparent to one skilled in the relevant art(s)how to implement alternative embodiments. Thus, the present embodimentsshould not be limited by any of the above described exemplaryembodiments.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU. S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35 U. S.C. 112. Claims that do not expressly include the phrase “means for” or“step for” are not to be interpreted under 35 U. S. C. 112.

What is claimed is:
 1. A method comprising: receiving, by a wirelessdevice, one or more messages comprising one or more configurationparameters of a cell, wherein the one or more configuration parametersindicate physical uplink shared channel (PUSCH) resources fortransmission of a message A (MsgA) payload of a two-step random-accessprocedure of the cell; transmitting, via a first PUSCH resource of thePUSCH resources, the MsgA payload for the two-step random-accessprocedure; and releasing the PUSCH resources based on completing thetwo-step random-access procedure.
 2. The method of claim 1, wherein thecompleting the two-step random-access procedure comprises at least oneof the following: receiving a first physical downlink control channel(PDCCH), for a first random-access response, identified by a cell RadioNetwork Temporary Identifier (C-RNTI); receiving a second PDCCH, for asecond random-access response, identified by a Radio Network TemporaryIdentifier (RNTI); or reaching a maximum number of preambletransmissions on a preamble transmission counter.
 3. The method of claim1, wherein the completing the two-step random-access procedure comprisesreceiving a second PDCCH, for a second random-access response,identified by a Radio Network Temporary Identifier (RNTI), and whereinthe RNTI is a message B RNTI (MSGB-RNTI).
 4. The method of claim 1,wherein the two-step random-access procedure is a contention-freetwo-step random-access procedure.
 5. The method of claim 1, wherein thereleasing the PUSCH resources comprises releasing a configuration of thePUSCH resources.
 6. The method of claim 5, further comprising:receiving, after the releasing the configuration, one or more secondmessages comprising one or more second configuration parametersindicating second PUSCH resources for transmission of a second MsgApayload of a second two-step random-access procedure of the cell; andtransmitting, via a second PUSCH resource of the second PUSCH resources,the second MsgA payload for the second two-step random-access procedure.7. The method of claim 1, wherein the releasing the PUSCH resourcescomprises stopping transmitting, via a PUSCH resource of the PUSCHresources, the MsgA payload.
 8. The method of claim 1, wherein the PUSCHresources comprise PUSCH occasions, and wherein the transmitting via thefirst PUSCH resource of the PUSCH resources comprises: transmitting viaa PUSCH occasion of the PUSCH occasions.
 9. The method of claim 1,wherein the one or more configuration parameters further indicate one ormore physical random-access channel (PRACH) resources.
 10. The method ofclaim 9, further comprising discarding the one or more PRACH resourcesbased on the completing the two-step random-access procedure.
 11. Themethod of claim 10, wherein the releasing the PUSCH resources is furtherbased on the discarding the one or more PRACH resources.
 12. The methodof claim 9, further comprising selecting, for the two-step random-accessprocedure, a PRACH resource of the one or more PRACH resources, whereinthe PRACH resource comprises: a preamble; and a PRACH occasion.
 13. Themethod of claim 12, further comprising transmitting the preamble via thePRACH occasion for the two-step random-access procedure.
 14. The methodof claim 12, wherein the one or more configuration parameters furtherindicate one or more mappings between the one or more PRACH resourcesand the PUSCH resources.
 15. The method of claim 14, further comprisingselecting the first PUSCH resource based on the one or more mappings,wherein the PRACH resource is mapped to the first PUSCH resource. 16.The method of claim 15, wherein the PRACH resource is mapped to thefirst PUSCH resource comprises that the PRACH occasion of the PRACHresource is mapped to the first PUSCH resource.
 17. The method of claim15, wherein the PRACH resource is mapped to the first PUSCH resourcecomprises that the preamble of the PRACH resource is mapped to the firstPUSCH resource.
 18. The method of claim 1, wherein the completing thetwo-step random-access procedure comprises receiving a first PDCCH, fora first random-access response, identified by a C-RNTI, and wherein thereceiving the first PDCCH for the first random-access response comprisesreceiving the first random-access response scheduled by the first PDCCH.19. The method of claim 18, wherein the first PDCCH comprises an uplinkgrant.
 20. The method of claim 1, wherein the cell is an unlicensedcell.